On 9/1/26 8:09 AM, Ricardo B. Marlière (SUSE) wrote: > @@ -53,11 +54,21 @@ ip -netns $NS2 route add $RT2 via inet6 $H1_IP6 > # Make sure ns2 will respond with ICMP unreachable > ip netns exec $NS2 sysctl -qw net.ipv4.icmp_ratelimit=0 net.ipv4.ip_forward=1 > > -# Run the test - a ping runs in the background, and we capture ICMP responses > -# with tcpdump; -c 1 means it should exit on the first ping, but add a > timeout > -# in case something goes wrong > +# Run the test - start tcpdump and wait for it to be capturing before > +# sending any traffic. -c 1 means it should exit on the first ping, but add > +# a timeout in case something goes wrong > +ip netns exec $NS1 timeout 10 tcpdump -tpni veth0 -c 1 \ > + 'icmp and icmp[icmptype] != icmp-echo' > $TMPFILE 2>$TCPDUMP_ERR &
Why keep the 'timeout 10'? > +TCPDUMP_PID=$! You have the pid. You can always kill it after the ping command if it does not terminate on its own after the 1 packet is received. > +if ! slowwait 3 grep -qs "listening" "$TCPDUMP_ERR"; then > + echo "FAIL - tcpdump did not start listening" > + cat "$TCPDUMP_ERR" > + exit 1 > +fi > + > ip netns exec $NS1 ping -w 3 -i 0.5 $PINGADDR >/dev/null & > -ip netns exec $NS1 timeout 10 tcpdump -tpni veth0 -c 1 'icmp and > icmp[icmptype] != icmp-echo' > $TMPFILE 2>/dev/null > + > +wait $TCPDUMP_PID >
