tests: Wait for NDPs to be sent in tunnel-push-pop-ipv6.
Otherwise the tests can fail under heavy load (or with valgrind).
@@ -45,6 +45,11 @@ dnl Check Neighbour discovery.
AT_CHECK([ovs-vsctl -- set Interface p0 options:pcap=p0.pcap])
AT_CHECK([ovs-appctl netdev-dummy/receive int-br 'in_port(2),eth(src=aa:55:aa:55:00:00,dst=f8:bc:12:ff:ff:ff),eth_type(0x0800),ipv4(src=1.1.3.92,dst=1.1.3.88,proto=1,tos=0,ttl=64,frag=no),icmp(type=0,code=0)'])
+
+dnl Wait for the two Neighbor Solicitation packets to be sent.
+dnl Sometimes the system can be slow (e.g. under valgrind)
+OVS_WAIT_UNTIL([test `ovs-pcap p0.pcap | sort | uniq | wc -l` -ge 2])
+
AT_CHECK([ovs-pcap p0.pcap > p0.pcap.txt 2>&1])
AT_CHECK([cat p0.pcap.txt | grep 92aa55aa55000086dd6000000000203aff2001cafe | uniq], [0], [dnl
