diff mbox series

[08/11] selftests: net/fcnal: Replace sleep after server start with -k

Message ID ec40bd7128a30e93b90ba888f3468f394617a010.1633520807.git.cdleonard@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series selftests: Improve nettest and net/fcnal-test.sh | expand

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Commit Message

Leonard Crestez Oct. 6, 2021, 11:47 a.m. UTC 
The -k switch makes the server fork into the background after the listen
call is succesful, this can be used to replace most of the `sleep 1`
statements in this script.

Change performed with a vim command:

s/nettest \(.*-s.*\) &\n\s*sleep 1\n/nettest \1 -k\r

Signed-off-by: Leonard Crestez <cdleonard@gmail.com>
---
 tools/testing/selftests/net/fcnal-test.sh | 641 ++++++++--------------
 1 file changed, 219 insertions(+), 422 deletions(-)

Comments

David Ahern Oct. 6, 2021, 2:54 p.m. UTC | #1 
On 10/6/21 5:47 AM, Leonard Crestez wrote:
> The -k switch makes the server fork into the background after the listen
> call is succesful, this can be used to replace most of the `sleep 1`
> statements in this script.
> 
> Change performed with a vim command:
> 
> s/nettest \(.*-s.*\) &\n\s*sleep 1\n/nettest \1 -k\r
> 
> Signed-off-by: Leonard Crestez <cdleonard@gmail.com>
> ---
>  tools/testing/selftests/net/fcnal-test.sh | 641 ++++++++--------------
>  1 file changed, 219 insertions(+), 422 deletions(-)
> 

I have a change from January [1] that runs the tests with 1 binary -
takes both client and server side arguments, does the server setup,
switches namespaces as needed and then runs the client side. I got
bogged down validating the before and after which takes a long time
given the number of tests. The output in verbose mode is as important as
the pass / fail. Many of the tests document existing behavior as well as
intended behavior.

You used a search and replace to update the tests. Did you then do the
compare of test results - not pass / fail but output?


[1]
https://github.com/dsahern/linux/commit/8e16fbab1eb224298e3324a9ddf38e27eee439c7
Leonard Crestez Oct. 6, 2021, 9:35 p.m. UTC | #2 
On 06.10.2021 17:54, David Ahern wrote:
> On 10/6/21 5:47 AM, Leonard Crestez wrote:
>> The -k switch makes the server fork into the background after the listen
>> call is succesful, this can be used to replace most of the `sleep 1`
>> statements in this script.
>>
>> Change performed with a vim command:
>>
>> s/nettest \(.*-s.*\) &\n\s*sleep 1\n/nettest \1 -k\r
>>
>> Signed-off-by: Leonard Crestez <cdleonard@gmail.com>
>> ---
>>   tools/testing/selftests/net/fcnal-test.sh | 641 ++++++++--------------
>>   1 file changed, 219 insertions(+), 422 deletions(-)
>>
> 
> I have a change from January [1] that runs the tests with 1 binary -
> takes both client and server side arguments, does the server setup,
> switches namespaces as needed and then runs the client side. I got
> bogged down validating the before and after which takes a long time
> given the number of tests. The output in verbose mode is as important as
> the pass / fail. Many of the tests document existing behavior as well as
> intended behavior.
> 
> You used a search and replace to update the tests. Did you then do the
> compare of test results - not pass / fail but output?

I counted the [FAIL] or [ OK ] markers but not the output of nettest 
itself. I don't know what to look for, I guess I could diff the outputs?

Shouldn't it be sufficient to compare the exit codes of the nettest client?

The output is also modified by a previous change to not capture server 
output separately and instead let it be combined with that of the 
client. That change is required for this one, doing out=$(nettest -k) 
does not return on fork unless the pipe is also closed.

I did not look at your change, mine is relatively minimal because it 
only changes who decide when the server goes into the background: the 
shell script or the server itself. This makes it work very easily even 
for tests with multiple server instances.

--
Regards,
Leonard
David Ahern Oct. 7, 2021, 1:22 a.m. UTC | #3 
On 10/6/21 3:35 PM, Leonard Crestez wrote:
> 
> I counted the [FAIL] or [ OK ] markers but not the output of nettest
> itself. I don't know what to look for, I guess I could diff the outputs?
> 
> Shouldn't it be sufficient to compare the exit codes of the nettest client?

mistakes happen. The 700+ tests that exist were verified by me when I
submitted the script - that each test passes when it should and fails
when it should. "FAIL" has many reasons. I tried to have separate exit
codes for nettest.c to capture the timeouts vs ECONNREFUSED, etc., but I
could easily have made a mistake. scanning the output is the best way.
Most of the 'supposed to fail' tests have a HINT saying why it should fail.

> 
> The output is also modified by a previous change to not capture server
> output separately and instead let it be combined with that of the
> client. That change is required for this one, doing out=$(nettest -k)
> does not return on fork unless the pipe is also closed.
> 
> I did not look at your change, mine is relatively minimal because it
> only changes who decide when the server goes into the background: the
> shell script or the server itself. This makes it work very easily even
> for tests with multiple server instances.

The logging issue is why I went with 1 binary do both server and client
after nettest.c got support for changing namespaces.
Leonard Crestez Nov. 10, 2021, 1:54 p.m. UTC | #4 
On 10/7/21 4:22 AM, David Ahern wrote:
> On 10/6/21 3:35 PM, Leonard Crestez wrote:
>>
>> I counted the [FAIL] or [ OK ] markers but not the output of nettest
>> itself. I don't know what to look for, I guess I could diff the outputs?
>>
>> Shouldn't it be sufficient to compare the exit codes of the nettest client?
> 
> mistakes happen. The 700+ tests that exist were verified by me when I
> submitted the script - that each test passes when it should and fails
> when it should. "FAIL" has many reasons. I tried to have separate exit
> codes for nettest.c to capture the timeouts vs ECONNREFUSED, etc., but I
> could easily have made a mistake. scanning the output is the best way.
> Most of the 'supposed to fail' tests have a HINT saying why it should fail.

It is not good to have a test for which correctness is ambiguous to such 
an extent, it makes reliable future changes difficult. In theory an 
uniform TAP format is supposed to solve this but it is not applied 
inside selftests/net.

I attempted to write a script to compare two logs in their current 
format: https://gitlab.com/cdleonard/kselftest-parse-nettest-fcnal

It does a bunch of nasty scrubbing of irrelevant behavior and got it to 
the point where no diffs are found between repeated runs on the same 
machine.

One nasty issue was that many tests kill processes inside log_test so 
relevant output may be shown either before or after the "TEST: " result 
line. This was solved by associating output until the next ### with 
previous test.

>> The output is also modified by a previous change to not capture server
>> output separately and instead let it be combined with that of the
>> client. That change is required for this one, doing out=$(nettest -k)
>> does not return on fork unless the pipe is also closed.
>>
>> I did not look at your change, mine is relatively minimal because it
>> only changes who decide when the server goes into the background: the
>> shell script or the server itself. This makes it work very easily even
>> for tests with multiple server instances.
> 
> The logging issue is why I went with 1 binary do both server and client
> after nettest.c got support for changing namespaces.

It's possible to just compare the "client" and "server" logs separately 
by sorting them on their prefix.

I think a decent approach would be to do a bulk replace for all 
"run_cmd{,_nsb,_nsc} nettest" with a new "run_nettest" function that 
passes all arguments to nettest itself. That run_nettest function could 
include a leading common "-t" arg that is parsed at the top of 
fcnal-test.sh.

--
Regards,
Leonard
diff mbox series

Patch

diff --git a/tools/testing/selftests/net/fcnal-test.sh b/tools/testing/selftests/net/fcnal-test.sh
index 09cb35e16219..e73aeb3884c5 100755
--- a/tools/testing/selftests/net/fcnal-test.sh
+++ b/tools/testing/selftests/net/fcnal-test.sh
@@ -804,63 +804,56 @@  ipv4_tcp_md5_novrf()
 	# single address
 	#
 
 	# basic use case
 	log_start
-	run_cmd nettest -s -M ${MD5_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -M ${MD5_PW} -m ${NSB_IP} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 0 "MD5: Single address config"
 
 	# client sends MD5, server not configured
 	log_start
 	show_hint "Should timeout due to MD5 mismatch"
-	run_cmd nettest -s &
-	sleep 1
+	run_cmd nettest -s -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: Server no config, client uses password"
 
 	# wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -s -M ${MD5_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -M ${MD5_PW} -m ${NSB_IP} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: Client uses wrong password"
 
 	# client from different address
 	log_start
 	show_hint "Should timeout due to MD5 mismatch"
-	run_cmd nettest -s -M ${MD5_PW} -m ${NSB_LO_IP} &
-	sleep 1
+	run_cmd nettest -s -M ${MD5_PW} -m ${NSB_LO_IP} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: Client address does not match address configured with password"
 
 	#
 	# MD5 extension - prefix length
 	#
 
 	# client in prefix
 	log_start
-	run_cmd nettest -s -M ${MD5_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -M ${MD5_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest  -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 0 "MD5: Prefix config"
 
 	# client in prefix, wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -s -M ${MD5_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -M ${MD5_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: Prefix config, client uses wrong password"
 
 	# client outside of prefix
 	log_start
 	show_hint "Should timeout due to MD5 mismatch"
-	run_cmd nettest -s -M ${MD5_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -M ${MD5_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest -c ${NSB_LO_IP} -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: Prefix config, client address not in configured prefix"
 }
 
 #
@@ -872,127 +865,112 @@  ipv4_tcp_md5()
 	# single address
 	#
 
 	# basic use case
 	log_start
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Single address config"
 
 	# client sends MD5, server not configured
 	log_start
 	show_hint "Should timeout since server does not have MD5 auth"
-	run_cmd nettest -s -I ${VRF} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Server no config, client uses password"
 
 	# wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Client uses wrong password"
 
 	# client from different address
 	log_start
 	show_hint "Should timeout since server config differs from client"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_LO_IP} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_LO_IP} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Client address does not match address configured with password"
 
 	#
 	# MD5 extension - prefix length
 	#
 
 	# client in prefix
 	log_start
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest  -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Prefix config"
 
 	# client in prefix, wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Prefix config, client uses wrong password"
 
 	# client outside of prefix
 	log_start
 	show_hint "Should timeout since client address is outside of prefix"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest -c ${NSB_LO_IP} -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Prefix config, client address not in configured prefix"
 
 	#
 	# duplicate config between default VRF and a VRF
 	#
 
 	log_start
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} -k
 	run_cmd_nsb nettest  -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Single address config in default VRF and VRF, conn in VRF"
 
 	log_start
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} -k
 	run_cmd_nsc nettest  -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 0 "MD5: VRF: Single address config in default VRF and VRF, conn in default VRF"
 
 	log_start
 	show_hint "Should timeout since client in default VRF uses VRF password"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} -k
 	run_cmd_nsc nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Single address config in default VRF and VRF, conn in default VRF with VRF pw"
 
 	log_start
 	show_hint "Should timeout since client in VRF uses default VRF password"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NSB_IP} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Single address config in default VRF and VRF, conn in VRF with default VRF pw"
 
 	log_start
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest  -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Prefix config in default VRF and VRF, conn in VRF"
 
 	log_start
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} -k
 	run_cmd_nsc nettest  -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 0 "MD5: VRF: Prefix config in default VRF and VRF, conn in default VRF"
 
 	log_start
 	show_hint "Should timeout since client in default VRF uses VRF password"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} -k
 	run_cmd_nsc nettest -r ${NSA_IP} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Prefix config in default VRF and VRF, conn in default VRF with VRF pw"
 
 	log_start
 	show_hint "Should timeout since client in VRF uses default VRF password"
-	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} &
-	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET} -k
+	run_cmd nettest -s -M ${MD5_WRONG_PW} -m ${NS_NET} -k
 	run_cmd_nsb nettest -r ${NSA_IP} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Prefix config in default VRF and VRF, conn in VRF with default VRF pw"
 
 	#
 	# negative tests
@@ -1015,20 +993,18 @@  ipv4_tcp_novrf()
 	# server tests
 	#
 	for a in ${NSA_IP} ${NSA_LO_IP}
 	do
 		log_start
-		run_cmd nettest -s &
-		sleep 1
+		run_cmd nettest -s -k
 		run_cmd_nsb nettest -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -I ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -I ${NSA_DEV} -k
 	run_cmd_nsb nettest -r ${a}
 	log_test_addr ${a} $? 0 "Device server"
 
 	# verify TCP reset sent and received
 	for a in ${NSA_IP} ${NSA_LO_IP}
@@ -1043,18 +1019,16 @@  ipv4_tcp_novrf()
 	# client
 	#
 	for a in ${NSB_IP} ${NSB_LO_IP}
 	do
 		log_start
-		run_cmd_nsb nettest -s &
-		sleep 1
+		run_cmd_nsb nettest -s -k
 		run_cmd nettest -r ${a} -0 ${NSA_IP}
 		log_test_addr ${a} $? 0 "Client"
 
 		log_start
-		run_cmd_nsb nettest -s &
-		sleep 1
+		run_cmd_nsb nettest -s -k
 		run_cmd nettest -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 0 "Client, device bind"
 
 		log_start
 		show_hint "Should fail 'Connection refused'"
@@ -1071,54 +1045,48 @@  ipv4_tcp_novrf()
 	# local address tests
 	#
 	for a in ${NSA_IP} ${NSA_LO_IP} 127.0.0.1
 	do
 		log_start
-		run_cmd nettest -s &
-		sleep 1
+		run_cmd nettest -s -k
 		run_cmd nettest -r ${a} -0 ${a} -1 ${a}
 		log_test_addr ${a} $? 0 "Global server, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -I ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -I ${NSA_DEV} -k
 	run_cmd nettest -r ${a} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, unbound client, local connection"
 
 	for a in ${NSA_LO_IP} 127.0.0.1
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since addresses on loopback are out of device scope"
-		run_cmd nettest -s -I ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -s -I ${NSA_DEV} -k
 		run_cmd nettest -r ${a}
 		log_test_addr ${a} $? 1 "Device server, unbound client, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s &
-	sleep 1
+	run_cmd nettest -s -k
 	run_cmd nettest -r ${a} -0 ${a} -d ${NSA_DEV}
 	log_test_addr ${a} $? 0 "Global server, device client, local connection"
 
 	for a in ${NSA_LO_IP} 127.0.0.1
 	do
 		log_start
 		show_hint "Should fail 'No route to host' since addresses on loopback are out of device scope"
-		run_cmd nettest -s &
-		sleep 1
+		run_cmd nettest -s -k
 		run_cmd nettest -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 1 "Global server, device client, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest  -d ${NSA_DEV} -r ${a} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, device client, local connection"
 
 	log_start
 	show_hint "Should fail 'Connection refused'"
@@ -1142,24 +1110,21 @@  ipv4_tcp_vrf()
 	#
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since global server with VRF is disabled"
-		run_cmd nettest -s &
-		sleep 1
+		run_cmd nettest -s -k
 		run_cmd_nsb nettest -r ${a}
 		log_test_addr ${a} $? 1 "Global server"
 
 		log_start
-		run_cmd nettest -s -I ${VRF} -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -s -I ${VRF} -3 ${VRF} -k
 		run_cmd_nsb nettest -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 
 		log_start
-		run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -r ${a}
 		log_test_addr ${a} $? 0 "Device server"
 
 		# verify TCP reset received
 		log_start
@@ -1171,12 +1136,11 @@  ipv4_tcp_vrf()
 	# local address tests
 	# (${VRF_IP} and 127.0.0.1 both timeout)
 	a=${NSA_IP}
 	log_start
 	show_hint "Should fail 'Connection refused' since global server with VRF is disabled"
-	run_cmd nettest -s &
-	sleep 1
+	run_cmd nettest -s -k
 	run_cmd nettest -r ${a} -d ${NSA_DEV}
 	log_test_addr ${a} $? 1 "Global server, local connection"
 
 	# run MD5 tests
 	ipv4_tcp_md5
@@ -1189,19 +1153,17 @@  ipv4_tcp_vrf()
 
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
 		show_hint "client socket should be bound to VRF"
-		run_cmd nettest -s -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -s -3 ${VRF} -k
 		run_cmd_nsb nettest -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 
 		log_start
 		show_hint "client socket should be bound to VRF"
-		run_cmd nettest -s -I ${VRF} -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -s -I ${VRF} -3 ${VRF} -k
 		run_cmd_nsb nettest -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 
 		# verify TCP reset received
 		log_start
@@ -1211,40 +1173,36 @@  ipv4_tcp_vrf()
 	done
 
 	a=${NSA_IP}
 	log_start
 	show_hint "client socket should be bound to device"
-	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd_nsb nettest -r ${a}
 	log_test_addr ${a} $? 0 "Device server"
 
 	# local address tests
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since client is not bound to VRF"
-		run_cmd nettest -s -I ${VRF} &
-		sleep 1
+		run_cmd nettest -s -I ${VRF} -k
 		run_cmd nettest -r ${a}
 		log_test_addr ${a} $? 1 "Global server, local connection"
 	done
 
 	#
 	# client
 	#
 	for a in ${NSB_IP} ${NSB_LO_IP}
 	do
 		log_start
-		run_cmd_nsb nettest -s &
-		sleep 1
+		run_cmd_nsb nettest -s -k
 		run_cmd nettest -r ${a} -d ${VRF}
 		log_test_addr ${a} $? 0 "Client, VRF bind"
 
 		log_start
-		run_cmd_nsb nettest -s &
-		sleep 1
+		run_cmd_nsb nettest -s -k
 		run_cmd nettest -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 0 "Client, device bind"
 
 		log_start
 		show_hint "Should fail 'Connection refused'"
@@ -1258,39 +1216,34 @@  ipv4_tcp_vrf()
 	done
 
 	for a in ${NSA_IP} ${VRF_IP} 127.0.0.1
 	do
 		log_start
-		run_cmd nettest -s -I ${VRF} -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -s -I ${VRF} -3 ${VRF} -k
 		run_cmd nettest -r ${a} -d ${VRF} -0 ${a}
 		log_test_addr ${a} $? 0 "VRF server, VRF client, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -I ${VRF} -3 ${VRF} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -3 ${VRF} -k
 	run_cmd nettest -r ${a} -d ${NSA_DEV} -0 ${a}
 	log_test_addr ${a} $? 0 "VRF server, device client, local connection"
 
 	log_start
 	show_hint "Should fail 'No route to host' since client is out of VRF scope"
-	run_cmd nettest -s -I ${VRF} &
-	sleep 1
+	run_cmd nettest -s -I ${VRF} -k
 	run_cmd nettest -r ${a}
 	log_test_addr ${a} $? 1 "VRF server, unbound client, local connection"
 
 	log_start
-	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -r ${a} -d ${VRF} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, VRF client, local connection"
 
 	log_start
-	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -r ${a} -d ${NSA_DEV} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, device client, local connection"
 }
 
 ipv4_tcp()
@@ -1324,12 +1277,11 @@  ipv4_udp_novrf()
 	# server tests
 	#
 	for a in ${NSA_IP} ${NSA_LO_IP}
 	do
 		log_start
-		run_cmd nettest -D -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -D -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 
 		log_start
 		show_hint "Should fail 'Connection refused' since there is no server"
@@ -1337,41 +1289,36 @@  ipv4_udp_novrf()
 		log_test_addr ${a} $? 1 "No server"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 	run_cmd_nsb nettest -D -r ${a}
 	log_test_addr ${a} $? 0 "Device server"
 
 	#
 	# client
 	#
 	for a in ${NSB_IP} ${NSB_LO_IP}
 	do
 		log_start
-		run_cmd_nsb nettest -D -s &
-		sleep 1
+		run_cmd_nsb nettest -D -s -k
 		run_cmd nettest -D -r ${a} -0 ${NSA_IP}
 		log_test_addr ${a} $? 0 "Client"
 
 		log_start
-		run_cmd_nsb nettest -D -s &
-		sleep 1
+		run_cmd_nsb nettest -D -s -k
 		run_cmd nettest -D -r ${a} -d ${NSA_DEV} -0 ${NSA_IP}
 		log_test_addr ${a} $? 0 "Client, device bind"
 
 		log_start
-		run_cmd_nsb nettest -D -s &
-		sleep 1
+		run_cmd_nsb nettest -D -s -k
 		run_cmd nettest -D -r ${a} -d ${NSA_DEV} -C -0 ${NSA_IP}
 		log_test_addr ${a} $? 0 "Client, device send via cmsg"
 
 		log_start
-		run_cmd_nsb nettest -D -s &
-		sleep 1
+		run_cmd_nsb nettest -D -s -k
 		run_cmd nettest -D -r ${a} -d ${NSA_DEV} -S -0 ${NSA_IP}
 		log_test_addr ${a} $? 0 "Client, device bind via IP_UNICAST_IF"
 
 		log_start
 		show_hint "Should fail 'Connection refused'"
@@ -1388,83 +1335,73 @@  ipv4_udp_novrf()
 	# local address tests
 	#
 	for a in ${NSA_IP} ${NSA_LO_IP} 127.0.0.1
 	do
 		log_start
-		run_cmd nettest -D -s &
-		sleep 1
+		run_cmd nettest -D -s -k
 		run_cmd nettest -D -r ${a} -0 ${a} -1 ${a}
 		log_test_addr ${a} $? 0 "Global server, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -r ${a}
 	log_test_addr ${a} $? 0 "Device server, unbound client, local connection"
 
 	for a in ${NSA_LO_IP} 127.0.0.1
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since address is out of device scope"
-		run_cmd nettest -s -D -I ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -s -D -I ${NSA_DEV} -k
 		run_cmd nettest -D -r ${a}
 		log_test_addr ${a} $? 1 "Device server, unbound client, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -D &
-	sleep 1
+	run_cmd nettest -s -D -k
 	run_cmd nettest -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "Global server, device client, local connection"
 
 	log_start
-	run_cmd nettest -s -D &
-	sleep 1
+	run_cmd nettest -s -D -k
 	run_cmd nettest -D -d ${NSA_DEV} -C -r ${a}
 	log_test_addr ${a} $? 0 "Global server, device send via cmsg, local connection"
 
 	log_start
-	run_cmd nettest -s -D &
-	sleep 1
+	run_cmd nettest -s -D -k
 	run_cmd nettest -D -d ${NSA_DEV} -S -r ${a}
 	log_test_addr ${a} $? 0 "Global server, device client via IP_UNICAST_IF, local connection"
 
 	# IPv4 with device bind has really weird behavior - it overrides the
 	# fib lookup, generates an rtable and tries to send the packet. This
 	# causes failures for local traffic at different places
 	for a in ${NSA_LO_IP} 127.0.0.1
 	do
 		log_start
 		show_hint "Should fail since addresses on loopback are out of device scope"
-		run_cmd nettest -D -s &
-		sleep 1
+		run_cmd nettest -D -s -k
 		run_cmd nettest -D -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 2 "Global server, device client, local connection"
 
 		log_start
 		show_hint "Should fail since addresses on loopback are out of device scope"
-		run_cmd nettest -D -s &
-		sleep 1
+		run_cmd nettest -D -s -k
 		run_cmd nettest -D -r ${a} -d ${NSA_DEV} -C
 		log_test_addr ${a} $? 1 "Global server, device send via cmsg, local connection"
 
 		log_start
 		show_hint "Should fail since addresses on loopback are out of device scope"
-		run_cmd nettest -D -s &
-		sleep 1
+		run_cmd nettest -D -s -k
 		run_cmd nettest -D -r ${a} -d ${NSA_DEV} -S
 		log_test_addr ${a} $? 1 "Global server, device client via IP_UNICAST_IF, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -D -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -D -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${NSA_DEV} -r ${a} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, device client, local conn"
 
 	log_start
 	run_cmd nettest -D -d ${NSA_DEV} -r ${a}
@@ -1484,63 +1421,55 @@  ipv4_udp_vrf()
 	#
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
 		show_hint "Fails because ingress is in a VRF and global server is disabled"
-		run_cmd nettest -D -s &
-		sleep 1
+		run_cmd nettest -D -s -k
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 1 "Global server"
 
 		log_start
-		run_cmd nettest -D -I ${VRF} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -D -I ${VRF} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 
 		log_start
-		run_cmd nettest -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 0 "Enslaved device server"
 
 		log_start
 		show_hint "Should fail 'Connection refused' since there is no server"
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 1 "No server"
 
 		log_start
 		show_hint "Should fail 'Connection refused' since global server is out of scope"
-		run_cmd nettest -D -s &
-		sleep 1
+		run_cmd nettest -D -s -k
 		run_cmd nettest -D -d ${VRF} -r ${a}
 		log_test_addr ${a} $? 1 "Global server, VRF client, local connection"
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, enslaved device client, local connection"
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "Enslaved device server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "Enslaved device server, device client, local conn"
 
 	# enable global server
 	log_subsection "Global server enabled"
@@ -1550,24 +1479,21 @@  ipv4_udp_vrf()
 	# server tests
 	#
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
-		run_cmd nettest -D -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -D -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 
 		log_start
-		run_cmd nettest -D -I ${VRF} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -D -I ${VRF} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 
 		log_start
-		run_cmd nettest -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -D -r ${a}
 		log_test_addr ${a} $? 0 "Enslaved device server"
 
 		log_start
 		show_hint "Should fail 'Connection refused'"
@@ -1577,18 +1503,16 @@  ipv4_udp_vrf()
 
 	#
 	# client tests
 	#
 	log_start
-	run_cmd_nsb nettest -D -s &
-	sleep 1
+	run_cmd_nsb nettest -D -s -k
 	run_cmd nettest -d ${VRF} -D -r ${NSB_IP} -1 ${NSA_IP}
 	log_test $? 0 "VRF client"
 
 	log_start
-	run_cmd_nsb nettest -D -s &
-	sleep 1
+	run_cmd_nsb nettest -D -s -k
 	run_cmd nettest -d ${NSA_DEV} -D -r ${NSB_IP} -1 ${NSA_IP}
 	log_test $? 0 "Enslaved device client"
 
 	# negative test - should fail
 	log_start
@@ -1604,53 +1528,46 @@  ipv4_udp_vrf()
 	#
 	# local address tests
 	#
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest -D -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -D -s -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "Global server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${VRF} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, device client, local conn"
 
 	log_start
-	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "Enslaved device server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -s -D -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "Enslaved device server, device client, local conn"
 
 	for a in ${VRF_IP} 127.0.0.1
 	do
 		log_start
-		run_cmd nettest -D -s -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -D -s -3 ${VRF} -k
 		run_cmd nettest -D -d ${VRF} -r ${a}
 		log_test_addr ${a} $? 0 "Global server, VRF client, local conn"
 	done
 
 	for a in ${VRF_IP} 127.0.0.1
 	do
 		log_start
-		run_cmd nettest -s -D -I ${VRF} -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -s -D -I ${VRF} -3 ${VRF} -k
 		run_cmd nettest -D -d ${VRF} -r ${a}
 		log_test_addr ${a} $? 0 "VRF server, VRF client, local conn"
 	done
 
 	# negative test - should fail
@@ -1807,12 +1724,11 @@  ipv4_rt()
 	# server tests
 	#
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
-		run_cmd nettest ${varg} -s &
-		sleep 1
+		run_cmd nettest ${varg} -s -k
 		run_cmd_nsb nettest ${varg} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, global server"
@@ -1821,12 +1737,11 @@  ipv4_rt()
 	done
 
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
-		run_cmd nettest ${varg} -s -I ${VRF} &
-		sleep 1
+		run_cmd nettest ${varg} -s -I ${VRF} -k
 		run_cmd_nsb nettest ${varg} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, VRF server"
@@ -1834,12 +1749,11 @@  ipv4_rt()
 		setup ${with_vrf}
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest ${varg} -s -I ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest ${varg} -s -I ${NSA_DEV} -k
 	run_cmd_nsb nettest ${varg} -r ${a} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, enslaved device server"
@@ -1848,23 +1762,21 @@  ipv4_rt()
 
 	#
 	# client test
 	#
 	log_start
-	run_cmd_nsb nettest ${varg} -s &
-	sleep 1
+	run_cmd_nsb nettest ${varg} -s -k
 	run_cmd nettest ${varg} -d ${VRF} -r ${NSB_IP} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, VRF client"
 
 	setup ${with_vrf}
 
 	log_start
-	run_cmd_nsb nettest ${varg} -s &
-	sleep 1
+	run_cmd_nsb nettest ${varg} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${NSB_IP} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, enslaved device client"
@@ -1875,12 +1787,11 @@  ipv4_rt()
 	# local address tests
 	#
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
-		run_cmd nettest ${varg} -s &
-		sleep 1
+		run_cmd nettest ${varg} -s -k
 		run_cmd nettest ${varg} -d ${VRF} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, global server, VRF client, local"
@@ -1889,12 +1800,11 @@  ipv4_rt()
 	done
 
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
-		run_cmd nettest ${varg} -I ${VRF} -s &
-		sleep 1
+		run_cmd nettest ${varg} -I ${VRF} -s -k
 		run_cmd nettest ${varg} -d ${VRF} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, VRF server and client, local"
@@ -1902,34 +1812,31 @@  ipv4_rt()
 		setup ${with_vrf}
 	done
 
 	a=${NSA_IP}
 	log_start
-	run_cmd nettest ${varg} -s &
-	sleep 1
+	run_cmd nettest ${varg} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${a} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, global server, enslaved device client, local"
 
 	setup ${with_vrf}
 
 	log_start
-	run_cmd nettest ${varg} -I ${VRF} -s &
-	sleep 1
+	run_cmd nettest ${varg} -I ${VRF} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${a} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, VRF server, enslaved device client, local"
 
 	setup ${with_vrf}
 
 	log_start
-	run_cmd nettest ${varg} -I ${NSA_DEV} -s &
-	sleep 1
+	run_cmd nettest ${varg} -I ${NSA_DEV} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${a} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, enslaved device server and client, local"
@@ -2268,63 +2175,56 @@  ipv6_tcp_md5_novrf()
 	# single address
 	#
 
 	# basic use case
 	log_start
-	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NSB_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 0 "MD5: Single address config"
 
 	# client sends MD5, server not configured
 	log_start
 	show_hint "Should timeout due to MD5 mismatch"
-	run_cmd nettest -6 -s &
-	sleep 1
+	run_cmd nettest -6 -s -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: Server no config, client uses password"
 
 	# wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NSB_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: Client uses wrong password"
 
 	# client from different address
 	log_start
 	show_hint "Should timeout due to MD5 mismatch"
-	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NSB_LO_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NSB_LO_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: Client address does not match address configured with password"
 
 	#
 	# MD5 extension - prefix length
 	#
 
 	# client in prefix
 	log_start
-	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 0 "MD5: Prefix config"
 
 	# client in prefix, wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: Prefix config, client uses wrong password"
 
 	# client outside of prefix
 	log_start
 	show_hint "Should timeout due to MD5 mismatch"
-	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -M ${MD5_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -c ${NSB_LO_IP6} -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: Prefix config, client address not in configured prefix"
 }
 
 #
@@ -2336,127 +2236,112 @@  ipv6_tcp_md5()
 	# single address
 	#
 
 	# basic use case
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Single address config"
 
 	# client sends MD5, server not configured
 	log_start
 	show_hint "Should timeout since server does not have MD5 auth"
-	run_cmd nettest -6 -s -I ${VRF} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Server no config, client uses password"
 
 	# wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Client uses wrong password"
 
 	# client from different address
 	log_start
 	show_hint "Should timeout since server config differs from client"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_LO_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_LO_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Client address does not match address configured with password"
 
 	#
 	# MD5 extension - prefix length
 	#
 
 	# client in prefix
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Prefix config"
 
 	# client in prefix, wrong password
 	log_start
 	show_hint "Should timeout since client uses wrong password"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Prefix config, client uses wrong password"
 
 	# client outside of prefix
 	log_start
 	show_hint "Should timeout since client address is outside of prefix"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -c ${NSB_LO_IP6} -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Prefix config, client address not in configured prefix"
 
 	#
 	# duplicate config between default VRF and a VRF
 	#
 
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Single address config in default VRF and VRF, conn in VRF"
 
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} -k
 	run_cmd_nsc nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 0 "MD5: VRF: Single address config in default VRF and VRF, conn in default VRF"
 
 	log_start
 	show_hint "Should timeout since client in default VRF uses VRF password"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} -k
 	run_cmd_nsc nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Single address config in default VRF and VRF, conn in default VRF with VRF pw"
 
 	log_start
 	show_hint "Should timeout since client in VRF uses default VRF password"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NSB_IP6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NSB_IP6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Single address config in default VRF and VRF, conn in VRF with default VRF pw"
 
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 0 "MD5: VRF: Prefix config in default VRF and VRF, conn in VRF"
 
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} -k
 	run_cmd_nsc nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 0 "MD5: VRF: Prefix config in default VRF and VRF, conn in default VRF"
 
 	log_start
 	show_hint "Should timeout since client in default VRF uses VRF password"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} -k
 	run_cmd_nsc nettest -6 -r ${NSA_IP6} -X ${MD5_PW}
 	log_test $? 2 "MD5: VRF: Prefix config in default VRF and VRF, conn in default VRF with VRF pw"
 
 	log_start
 	show_hint "Should timeout since client in VRF uses default VRF password"
-	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} &
-	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -M ${MD5_PW} -m ${NS_NET6} -k
+	run_cmd nettest -6 -s -M ${MD5_WRONG_PW} -m ${NS_NET6} -k
 	run_cmd_nsb nettest -6 -r ${NSA_IP6} -X ${MD5_WRONG_PW}
 	log_test $? 2 "MD5: VRF: Prefix config in default VRF and VRF, conn in VRF with default VRF pw"
 
 	#
 	# negative tests
@@ -2479,12 +2364,11 @@  ipv6_tcp_novrf()
 	# server tests
 	#
 	for a in ${NSA_IP6} ${NSA_LO_IP6} ${NSA_LINKIP6}%${NSB_DEV}
 	do
 		log_start
-		run_cmd nettest -6 -s &
-		sleep 1
+		run_cmd nettest -6 -s -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 	done
 
 	# verify TCP reset received
@@ -2500,21 +2384,19 @@  ipv6_tcp_novrf()
 	# client
 	#
 	for a in ${NSB_IP6} ${NSB_LO_IP6} ${NSB_LINKIP6}%${NSA_DEV}
 	do
 		log_start
-		run_cmd_nsb nettest -6 -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -s -k
 		run_cmd nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "Client"
 	done
 
 	for a in ${NSB_IP6} ${NSB_LO_IP6} ${NSB_LINKIP6}%${NSA_DEV}
 	do
 		log_start
-		run_cmd_nsb nettest -6 -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -s -k
 		run_cmd nettest -6 -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 0 "Client, device bind"
 	done
 
 	for a in ${NSB_IP6} ${NSB_LO_IP6} ${NSB_LINKIP6}%${NSA_DEV}
@@ -2529,55 +2411,49 @@  ipv6_tcp_novrf()
 	# local address tests
 	#
 	for a in ${NSA_IP6} ${NSA_LO_IP6} ::1
 	do
 		log_start
-		run_cmd nettest -6 -s &
-		sleep 1
+		run_cmd nettest -6 -s -k
 		run_cmd nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "Global server, local connection"
 	done
 
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -r ${a} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, unbound client, local connection"
 
 	for a in ${NSA_LO_IP6} ::1
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since addresses on loopback are out of device scope"
-		run_cmd nettest -6 -s -I ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${NSA_DEV} -k
 		run_cmd nettest -6 -r ${a}
 		log_test_addr ${a} $? 1 "Device server, unbound client, local connection"
 	done
 
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -s &
-	sleep 1
+	run_cmd nettest -6 -s -k
 	run_cmd nettest -6 -r ${a} -d ${NSA_DEV} -0 ${a}
 	log_test_addr ${a} $? 0 "Global server, device client, local connection"
 
 	for a in ${NSA_LO_IP6} ::1
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since addresses on loopback are out of device scope"
-		run_cmd nettest -6 -s &
-		sleep 1
+		run_cmd nettest -6 -s -k
 		run_cmd nettest -6 -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 1 "Global server, device client, local connection"
 	done
 
 	for a in ${NSA_IP6} ${NSA_LINKIP6}
 	do
 		log_start
-		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 		run_cmd nettest -6  -d ${NSA_DEV} -r ${a}
 		log_test_addr ${a} $? 0 "Device server, device client, local conn"
 	done
 
 	for a in ${NSA_IP6} ${NSA_LINKIP6}
@@ -2605,38 +2481,34 @@  ipv6_tcp_vrf()
 	#
 	for a in ${NSA_IP6} ${VRF_IP6} ${NSA_LINKIP6}%${NSB_DEV}
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since global server with VRF is disabled"
-		run_cmd nettest -6 -s &
-		sleep 1
+		run_cmd nettest -6 -s -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 1 "Global server"
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 	done
 
 	# link local is always bound to ingress device
 	a=${NSA_LINKIP6}%${NSB_DEV}
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -3 ${NSA_DEV} -k
 	run_cmd_nsb nettest -6 -r ${a}
 	log_test_addr ${a} $? 0 "VRF server"
 
 	for a in ${NSA_IP6} ${VRF_IP6} ${NSA_LINKIP6}%${NSB_DEV}
 	do
 		log_start
-		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "Device server"
 	done
 
 	# verify TCP reset received
@@ -2650,12 +2522,11 @@  ipv6_tcp_vrf()
 
 	# local address tests
 	a=${NSA_IP6}
 	log_start
 	show_hint "Should fail 'Connection refused' since global server with VRF is disabled"
-	run_cmd nettest -6 -s &
-	sleep 1
+	run_cmd nettest -6 -s -k
 	run_cmd nettest -6 -r ${a} -d ${NSA_DEV}
 	log_test_addr ${a} $? 1 "Global server, local connection"
 
 	# run MD5 tests
 	ipv6_tcp_md5
@@ -2667,44 +2538,39 @@  ipv6_tcp_vrf()
 	set_sysctl net.ipv4.tcp_l3mdev_accept=1
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -s -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -6 -s -3 ${VRF} -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 	done
 
 	# For LLA, child socket is bound to device
 	a=${NSA_LINKIP6}%${NSB_DEV}
 	log_start
-	run_cmd nettest -6 -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -s -3 ${NSA_DEV} -k
 	run_cmd_nsb nettest -6 -r ${a}
 	log_test_addr ${a} $? 0 "Global server"
 
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -3 ${NSA_DEV} -k
 	run_cmd_nsb nettest -6 -r ${a}
 	log_test_addr ${a} $? 0 "VRF server"
 
 	for a in ${NSA_IP6} ${NSA_LINKIP6}%${NSB_DEV}
 	do
 		log_start
-		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 0 "Device server"
 	done
 
 	# verify TCP reset received
@@ -2719,12 +2585,11 @@  ipv6_tcp_vrf()
 	# local address tests
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
 		show_hint "Fails 'Connection refused' since client is not in VRF"
-		run_cmd nettest -6 -s -I ${VRF} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${VRF} -k
 		run_cmd nettest -6 -r ${a}
 		log_test_addr ${a} $? 1 "Global server, local connection"
 	done
 
 
@@ -2732,29 +2597,26 @@  ipv6_tcp_vrf()
 	# client
 	#
 	for a in ${NSB_IP6} ${NSB_LO_IP6}
 	do
 		log_start
-		run_cmd_nsb nettest -6 -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -s -k
 		run_cmd nettest -6 -r ${a} -d ${VRF}
 		log_test_addr ${a} $? 0 "Client, VRF bind"
 	done
 
 	a=${NSB_LINKIP6}
 	log_start
 	show_hint "Fails since VRF device does not allow linklocal addresses"
-	run_cmd_nsb nettest -6 -s &
-	sleep 1
+	run_cmd_nsb nettest -6 -s -k
 	run_cmd nettest -6 -r ${a} -d ${VRF}
 	log_test_addr ${a} $? 1 "Client, VRF bind"
 
 	for a in ${NSB_IP6} ${NSB_LO_IP6} ${NSB_LINKIP6}
 	do
 		log_start
-		run_cmd_nsb nettest -6 -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -s -k
 		run_cmd nettest -6 -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 0 "Client, device bind"
 	done
 
 	for a in ${NSB_IP6} ${NSB_LO_IP6}
@@ -2774,42 +2636,37 @@  ipv6_tcp_vrf()
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6} ::1
 	do
 		log_start
-		run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} -k
 		run_cmd nettest -6 -r ${a} -d ${VRF} -0 ${a}
 		log_test_addr ${a} $? 0 "VRF server, VRF client, local connection"
 	done
 
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -3 ${VRF} -k
 	run_cmd nettest -6 -r ${a} -d ${NSA_DEV} -0 ${a}
 	log_test_addr ${a} $? 0 "VRF server, device client, local connection"
 
 	a=${NSA_IP6}
 	log_start
 	show_hint "Should fail since unbound client is out of VRF scope"
-	run_cmd nettest -6 -s -I ${VRF} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${VRF} -k
 	run_cmd nettest -6 -r ${a}
 	log_test_addr ${a} $? 1 "VRF server, unbound client, local connection"
 
 	log_start
-	run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -r ${a} -d ${VRF} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, VRF client, local connection"
 
 	for a in ${NSA_IP6} ${NSA_LINKIP6}
 	do
 		log_start
-		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 		run_cmd nettest -6 -r ${a} -d ${NSA_DEV} -0 ${a}
 		log_test_addr ${a} $? 0 "Device server, device client, local connection"
 	done
 }
 
@@ -2844,26 +2701,23 @@  ipv6_udp_novrf()
 	# server tests
 	#
 	for a in ${NSA_IP6} ${NSA_LINKIP6}%${NSB_DEV}
 	do
 		log_start
-		run_cmd nettest -6 -D -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -D -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 
 		log_start
-		run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 0 "Device server"
 	done
 
 	a=${NSA_LO_IP6}
 	log_start
-	run_cmd nettest -6 -D -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -s -3 ${NSA_DEV} -k
 	run_cmd_nsb nettest -6 -D -r ${a}
 	log_test_addr ${a} $? 0 "Global server"
 
 	# should fail since loopback address is out of scope for a device
 	# bound server, but it does not - hence this is more documenting
@@ -2888,30 +2742,26 @@  ipv6_udp_novrf()
 	# client
 	#
 	for a in ${NSB_IP6} ${NSB_LO_IP6} ${NSB_LINKIP6}%${NSA_DEV}
 	do
 		log_start
-		run_cmd_nsb nettest -6 -D -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -0 ${NSA_IP6}
 		log_test_addr ${a} $? 0 "Client"
 
 		log_start
-		run_cmd_nsb nettest -6 -D -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -d ${NSA_DEV} -0 ${NSA_IP6}
 		log_test_addr ${a} $? 0 "Client, device bind"
 
 		log_start
-		run_cmd_nsb nettest -6 -D -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -d ${NSA_DEV} -C -0 ${NSA_IP6}
 		log_test_addr ${a} $? 0 "Client, device send via cmsg"
 
 		log_start
-		run_cmd_nsb nettest -6 -D -s &
-		sleep 1
+		run_cmd_nsb nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -d ${NSA_DEV} -S -0 ${NSA_IP6}
 		log_test_addr ${a} $? 0 "Client, device bind via IPV6_UNICAST_IF"
 
 		log_start
 		show_hint "Should fail 'Connection refused'"
@@ -2928,80 +2778,70 @@  ipv6_udp_novrf()
 	# local address tests
 	#
 	for a in ${NSA_IP6} ${NSA_LO_IP6} ::1
 	do
 		log_start
-		run_cmd nettest -6 -D -s &
-		sleep 1
+		run_cmd nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -0 ${a} -1 ${a}
 		log_test_addr ${a} $? 0 "Global server, local connection"
 	done
 
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -s -D -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -s -D -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -r ${a}
 	log_test_addr ${a} $? 0 "Device server, unbound client, local connection"
 
 	for a in ${NSA_LO_IP6} ::1
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since address is out of device scope"
-		run_cmd nettest -6 -s -D -I ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -s -D -I ${NSA_DEV} -k
 		run_cmd nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 1 "Device server, local connection"
 	done
 
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -s -D &
-	sleep 1
+	run_cmd nettest -6 -s -D -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "Global server, device client, local connection"
 
 	log_start
-	run_cmd nettest -6 -s -D &
-	sleep 1
+	run_cmd nettest -6 -s -D -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -C -r ${a}
 	log_test_addr ${a} $? 0 "Global server, device send via cmsg, local connection"
 
 	log_start
-	run_cmd nettest -6 -s -D &
-	sleep 1
+	run_cmd nettest -6 -s -D -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -S -r ${a}
 	log_test_addr ${a} $? 0 "Global server, device client via IPV6_UNICAST_IF, local connection"
 
 	for a in ${NSA_LO_IP6} ::1
 	do
 		log_start
 		show_hint "Should fail 'No route to host' since addresses on loopback are out of device scope"
-		run_cmd nettest -6 -D -s &
-		sleep 1
+		run_cmd nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -d ${NSA_DEV}
 		log_test_addr ${a} $? 1 "Global server, device client, local connection"
 
 		log_start
 		show_hint "Should fail 'No route to host' since addresses on loopback are out of device scope"
-		run_cmd nettest -6 -D -s &
-		sleep 1
+		run_cmd nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -d ${NSA_DEV} -C
 		log_test_addr ${a} $? 1 "Global server, device send via cmsg, local connection"
 
 		log_start
 		show_hint "Should fail 'No route to host' since addresses on loopback are out of device scope"
-		run_cmd nettest -6 -D -s &
-		sleep 1
+		run_cmd nettest -6 -D -s -k
 		run_cmd nettest -6 -D -r ${a} -d ${NSA_DEV} -S
 		log_test_addr ${a} $? 1 "Global server, device client via IP_UNICAST_IF, local connection"
 	done
 
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -D -s -I ${NSA_DEV} -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -s -I ${NSA_DEV} -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a} -0 ${a}
 	log_test_addr ${a} $? 0 "Device server, device client, local conn"
 
 	log_start
 	show_hint "Should fail 'Connection refused'"
@@ -3010,12 +2850,11 @@  ipv6_udp_novrf()
 
 	# LLA to GUA
 	run_cmd_nsb ip -6 addr del ${NSB_IP6}/64 dev ${NSB_DEV}
 	run_cmd_nsb ip -6 ro add ${NSA_IP6}/128 dev ${NSB_DEV}
 	log_start
-	run_cmd nettest -6 -s -D &
-	sleep 1
+	run_cmd nettest -6 -s -D -k
 	run_cmd_nsb nettest -6 -D -r ${NSA_IP6}
 	log_test $? 0 "UDP in - LLA to GUA"
 
 	run_cmd_nsb ip -6 ro del ${NSA_IP6}/128 dev ${NSB_DEV}
 	run_cmd_nsb ip -6 addr add ${NSB_IP6}/64 dev ${NSB_DEV}
@@ -3034,30 +2873,27 @@  ipv6_udp_vrf()
 	#
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since global server is disabled"
-		run_cmd nettest -6 -D -s &
-		sleep 1
+		run_cmd nettest -6 -D -s -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 1 "Global server"
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 0 "Enslaved device server"
 	done
 
 	# negative test - should fail
@@ -3074,48 +2910,42 @@  ipv6_udp_vrf()
 	#
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
 		show_hint "Should fail 'Connection refused' since global server is disabled"
-		run_cmd nettest -6 -D -s &
-		sleep 1
+		run_cmd nettest -6 -D -s -k
 		run_cmd nettest -6 -D -d ${VRF} -r ${a}
 		log_test_addr ${a} $? 1 "Global server, VRF client, local conn"
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -D -I ${VRF} -s &
-		sleep 1
+		run_cmd nettest -6 -D -I ${VRF} -s -k
 		run_cmd nettest -6 -D -d ${VRF} -r ${a}
 		log_test_addr ${a} $? 0 "VRF server, VRF client, local conn"
 	done
 
 	a=${NSA_IP6}
 	log_start
 	show_hint "Should fail 'Connection refused' since global server is disabled"
-	run_cmd nettest -6 -D -s &
-	sleep 1
+	run_cmd nettest -6 -D -s -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 1 "Global server, device client, local conn"
 
 	log_start
-	run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, device client, local conn"
 
 	log_start
-	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "Enslaved device server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "Enslaved device server, device client, local conn"
 
 	# disable global server
 	log_subsection "Global server enabled"
@@ -3125,30 +2955,27 @@  ipv6_udp_vrf()
 	# server tests
 	#
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -D -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -D -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 0 "Global server"
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 0 "VRF server"
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-		sleep 1
+		run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 		run_cmd_nsb nettest -6 -D -r ${a}
 		log_test_addr ${a} $? 0 "Enslaved device server"
 	done
 
 	# negative test - should fail
@@ -3161,23 +2988,21 @@  ipv6_udp_vrf()
 
 	#
 	# client tests
 	#
 	log_start
-	run_cmd_nsb nettest -6 -D -s &
-	sleep 1
+	run_cmd_nsb nettest -6 -D -s -k
 	run_cmd nettest -6 -D -d ${VRF} -r ${NSB_IP6}
 	log_test $? 0 "VRF client"
 
 	# negative test - should fail
 	log_start
 	run_cmd nettest -6 -D -d ${VRF} -r ${NSB_IP6}
 	log_test $? 1 "No server, VRF client"
 
 	log_start
-	run_cmd_nsb nettest -6 -D -s &
-	sleep 1
+	run_cmd_nsb nettest -6 -D -s -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${NSB_IP6}
 	log_test $? 0 "Enslaved device client"
 
 	# negative test - should fail
 	log_start
@@ -3187,32 +3012,28 @@  ipv6_udp_vrf()
 	#
 	# local address tests
 	#
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -D -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "Global server, VRF client, local conn"
 
 	#log_start
-	run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, VRF client, local conn"
 
 
 	a=${VRF_IP6}
 	log_start
-	run_cmd nettest -6 -D -s -3 ${VRF} &
-	sleep 1
+	run_cmd nettest -6 -D -s -3 ${VRF} -k
 	run_cmd nettest -6 -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "Global server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -6 -D -I ${VRF} -s -3 ${VRF} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${VRF} -s -3 ${VRF} -k
 	run_cmd nettest -6 -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, VRF client, local conn"
 
 	# negative test - should fail
 	for a in ${NSA_IP6} ${VRF_IP6}
@@ -3223,64 +3044,57 @@  ipv6_udp_vrf()
 	done
 
 	# device to global IP
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest -6 -D -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "Global server, device client, local conn"
 
 	log_start
-	run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${VRF} -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "VRF server, device client, local conn"
 
 	log_start
-	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${VRF} -r ${a}
 	log_test_addr ${a} $? 0 "Device server, VRF client, local conn"
 
 	log_start
-	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} &
-	sleep 1
+	run_cmd nettest -6 -D -I ${NSA_DEV} -s -3 ${NSA_DEV} -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 0 "Device server, device client, local conn"
 
 	log_start
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${a}
 	log_test_addr ${a} $? 1 "No server, device client, local conn"
 
 
 	# link local addresses
 	log_start
-	run_cmd nettest -6 -D -s &
-	sleep 1
+	run_cmd nettest -6 -D -s -k
 	run_cmd_nsb nettest -6 -D -d ${NSB_DEV} -r ${NSA_LINKIP6}
 	log_test $? 0 "Global server, linklocal IP"
 
 	log_start
 	run_cmd_nsb nettest -6 -D -d ${NSB_DEV} -r ${NSA_LINKIP6}
 	log_test $? 1 "No server, linklocal IP"
 
 
 	log_start
-	run_cmd_nsb nettest -6 -D -s &
-	sleep 1
+	run_cmd_nsb nettest -6 -D -s -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${NSB_LINKIP6}
 	log_test $? 0 "Enslaved device client, linklocal IP"
 
 	log_start
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${NSB_LINKIP6}
 	log_test $? 1 "No server, device client, peer linklocal IP"
 
 
 	log_start
-	run_cmd nettest -6 -D -s &
-	sleep 1
+	run_cmd nettest -6 -D -s -k
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${NSA_LINKIP6}
 	log_test $? 0 "Enslaved device client, local conn - linklocal IP"
 
 	log_start
 	run_cmd nettest -6 -D -d ${NSA_DEV} -r ${NSA_LINKIP6}
@@ -3288,12 +3102,11 @@  ipv6_udp_vrf()
 
 	# LLA to GUA
 	run_cmd_nsb ip -6 addr del ${NSB_IP6}/64 dev ${NSB_DEV}
 	run_cmd_nsb ip -6 ro add ${NSA_IP6}/128 dev ${NSB_DEV}
 	log_start
-	run_cmd nettest -6 -s -D &
-	sleep 1
+	run_cmd nettest -6 -s -D -k
 	run_cmd_nsb nettest -6 -D -r ${NSA_IP6}
 	log_test $? 0 "UDP in - LLA to GUA"
 
 	run_cmd_nsb ip -6 ro del ${NSA_IP6}/128 dev ${NSB_DEV}
 	run_cmd_nsb ip -6 addr add ${NSB_IP6}/64 dev ${NSB_DEV}
@@ -3443,12 +3256,11 @@  ipv6_rt()
 	# server tests
 	#
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest ${varg} -s &
-		sleep 1
+		run_cmd nettest ${varg} -s -k
 		run_cmd_nsb nettest ${varg} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, global server"
@@ -3457,12 +3269,11 @@  ipv6_rt()
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest ${varg} -I ${VRF} -s &
-		sleep 1
+		run_cmd nettest ${varg} -I ${VRF} -s -k
 		run_cmd_nsb nettest ${varg} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, VRF server"
@@ -3471,12 +3282,11 @@  ipv6_rt()
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest ${varg} -I ${NSA_DEV} -s &
-		sleep 1
+		run_cmd nettest ${varg} -I ${NSA_DEV} -s -k
 		run_cmd_nsb nettest ${varg} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, enslaved device server"
@@ -3486,23 +3296,21 @@  ipv6_rt()
 
 	#
 	# client test
 	#
 	log_start
-	run_cmd_nsb nettest ${varg} -s &
-	sleep 1
+	run_cmd_nsb nettest ${varg} -s -k
 	run_cmd nettest ${varg} -d ${VRF} -r ${NSB_IP6} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test  0 0 "${desc}, VRF client"
 
 	setup ${with_vrf}
 
 	log_start
-	run_cmd_nsb nettest ${varg} -s &
-	sleep 1
+	run_cmd_nsb nettest ${varg} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${NSB_IP6} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test  0 0 "${desc}, enslaved device client"
@@ -3514,12 +3322,11 @@  ipv6_rt()
 	# local address tests
 	#
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest ${varg} -s &
-		sleep 1
+		run_cmd nettest ${varg} -s -k
 		run_cmd nettest ${varg} -d ${VRF} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, global server, VRF client"
@@ -3528,12 +3335,11 @@  ipv6_rt()
 	done
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest ${varg} -I ${VRF} -s &
-		sleep 1
+		run_cmd nettest ${varg} -I ${VRF} -s -k
 		run_cmd nettest ${varg} -d ${VRF} -r ${a} &
 		sleep 3
 		run_cmd ip link del ${VRF}
 		sleep 1
 		log_test_addr ${a} 0 0 "${desc}, VRF server and client"
@@ -3541,34 +3347,31 @@  ipv6_rt()
 		setup ${with_vrf}
 	done
 
 	a=${NSA_IP6}
 	log_start
-	run_cmd nettest ${varg} -s &
-	sleep 1
+	run_cmd nettest ${varg} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${a} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, global server, device client"
 
 	setup ${with_vrf}
 
 	log_start
-	run_cmd nettest ${varg} -I ${VRF} -s &
-	sleep 1
+	run_cmd nettest ${varg} -I ${VRF} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${a} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, VRF server, device client"
 
 	setup ${with_vrf}
 
 	log_start
-	run_cmd nettest ${varg} -I ${NSA_DEV} -s &
-	sleep 1
+	run_cmd nettest ${varg} -I ${NSA_DEV} -s -k
 	run_cmd nettest ${varg} -d ${NSA_DEV} -r ${a} &
 	sleep 3
 	run_cmd ip link del ${VRF}
 	sleep 1
 	log_test_addr ${a} 0 0 "${desc}, device server, device client"
@@ -3622,12 +3425,11 @@  netfilter_tcp_reset()
 	local a
 
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
-		run_cmd nettest -s &
-		sleep 1
+		run_cmd nettest -s -k
 		run_cmd_nsb nettest -r ${a}
 		log_test_addr ${a} $? 1 "Global server, reject with TCP-reset on Rx"
 	done
 }
 
@@ -3640,12 +3442,11 @@  netfilter_icmp()
 	[ "${stype}" = "UDP" ] && arg="-D"
 
 	for a in ${NSA_IP} ${VRF_IP}
 	do
 		log_start
-		run_cmd nettest ${arg} -s &
-		sleep 1
+		run_cmd nettest ${arg} -s -k
 		run_cmd_nsb nettest ${arg} -r ${a}
 		log_test_addr ${a} $? 1 "Global ${stype} server, Rx reject icmp-port-unreach"
 	done
 }
 
@@ -3679,12 +3480,11 @@  netfilter_tcp6_reset()
 	local a
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -s &
-		sleep 1
+		run_cmd nettest -6 -s -k
 		run_cmd_nsb nettest -6 -r ${a}
 		log_test_addr ${a} $? 1 "Global server, reject with TCP-reset on Rx"
 	done
 }
 
@@ -3697,12 +3497,11 @@  netfilter_icmp6()
 	[ "${stype}" = "UDP" ] && arg="$arg -D"
 
 	for a in ${NSA_IP6} ${VRF_IP6}
 	do
 		log_start
-		run_cmd nettest -6 -s ${arg} &
-		sleep 1
+		run_cmd nettest -6 -s ${arg} -k
 		run_cmd_nsb nettest -6 ${arg} -r ${a}
 		log_test_addr ${a} $? 1 "Global ${stype} server, Rx reject icmp-port-unreach"
 	done
 }
 
@@ -3893,17 +3692,15 @@  use_case_snat_on_vrf()
 	local port="12345"
 
 	run_cmd iptables -t nat -A POSTROUTING -p tcp -m tcp --dport ${port} -j SNAT --to-source ${NSA_LO_IP} -o ${VRF}
 	run_cmd ip6tables -t nat -A POSTROUTING -p tcp -m tcp --dport ${port} -j SNAT --to-source ${NSA_LO_IP6} -o ${VRF}
 
-	run_cmd_nsb nettest -s -l ${NSB_IP} -p ${port} &
-	sleep 1
+	run_cmd_nsb nettest -s -l ${NSB_IP} -p ${port} -k
 	run_cmd nettest -d ${VRF} -r ${NSB_IP} -p ${port}
 	log_test $? 0 "IPv4 TCP connection over VRF with SNAT"
 
-	run_cmd_nsb nettest -6 -s -l ${NSB_IP6} -p ${port} &
-	sleep 1
+	run_cmd_nsb nettest -6 -s -l ${NSB_IP6} -p ${port} -k
 	run_cmd nettest -6 -d ${VRF} -r ${NSB_IP6} -p ${port}
 	log_test $? 0 "IPv6 TCP connection over VRF with SNAT"
 
 	# Cleanup
 	run_cmd iptables -t nat -D POSTROUTING -p tcp -m tcp --dport ${port} -j SNAT --to-source ${NSA_LO_IP} -o ${VRF}