No flow for arp from qg-xxx

[yalei wang]

I followed the default config in devstack，enabled the legacy snat app,and find the VM could ping the qg on br-int which in qrouter namespace， but could not ping the ip on br-ex, after some investigation, I find the arp from qg was dropped by flow table 5 of br-int.
There is no flow to handle the package from qg，is that expected behavior？

the last line drop the pkg
==================================
 cookie=0x0, table=0, n_packets=1, n_bytes=42, priority=100,arp,in_port=5 actions=resubmit(,40),IN_PORT
 cookie=0x0, table=0, n_packets=120, n_bytes=12565, priority=100,ip,in_port=5 actions=resubmit(,40),resubmit(,115)
 cookie=0x0, table=0, n_packets=0, n_bytes=0, priority=100,arp,in_port=12 actions=resubmit(,40),IN_PORT
 cookie=0x0, table=0, n_packets=0, n_bytes=0, priority=100,ip,in_port=12 actions=resubmit(,40),resubmit(,115)
 cookie=0x0, table=0, n_packets=0, n_bytes=0, priority=100,arp,in_port=14 actions=resubmit(,40),IN_PORT
 cookie=0x0, table=0, n_packets=0, n_bytes=0, priority=100,ip,in_port=14 actions=resubmit(,40),resubmit(,115)
 cookie=0x0, table=0, n_packets=0, n_bytes=0, priority=100,tun_id=0x17,in_port=2 actions=load:0x1->OXM_OF_METADATA[],resubmit(,100)
 cookie=0x0, table=0, n_packets=44792, n_bytes=4316815, priority=100,in_port=9 actions=load:0x6->NXM_NX_REG6[],load:0x1->OXM_OF_METADATA[],load:0->OXM_OF_IN_PORT[],resubmit(,)
 cookie=0x0, table=0, n_packets=5, n_bytes=526, priority=100,in_port=8 actions=load:0x5->NXM_NX_REG6[],load:0x1->OXM_OF_METADATA[],load:0->OXM_OF_IN_PORT[],resubmit(,)
 cookie=0x0, table=0, n_packets=4749, n_bytes=461542, priority=100,in_port=6 actions=load:0x3->NXM_NX_REG6[],load:0x1->OXM_OF_METADATA[],load:0->OXM_OF_IN_PORT[],resubmit(,)
 cookie=0x0, table=0, n_packets=19543, n_bytes=1135134, priority=50,in_port=1,vlan_tci=0x0000/0x1fff actions=load:0->OXM_OF_IN_PORT[],load:0x2->OXM_OF_METADATA[],resubmit(,55)
 cookie=0x0, table=0, n_packets=50342, n_bytes=4817007, priority=1 actions=resubmit(,5)
 cookie=0x0, table=5, n_packets=180, n_bytes=17440, priority=300,tcp,nw_dst=169.254.169.254,tp_dst=80 actions=resubmit(,20)
 cookie=0x0, table=5, n_packets=3114, n_bytes=306572, priority=200,reg6=0x3 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=5, n_bytes=526, priority=200,reg6=0x5 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,reg6=0xb actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=43247, n_bytes=4240415, priority=200,ip,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7,nw_src=10.0.0.8 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=1349, n_bytes=56658, priority=200,arp,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7,arp_spa=10.0.0.8,arp_sha=fa:16:3e:e3:bb:f7 actions=resubmit(,20)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,ipv6,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7,ipv6_src=fd83:7ceb:d00d:0:f816:3eff:fee3:bbf7 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,icmp6,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7,ipv6_src=fd83:7ceb:d00d:0:f816:3eff:fee3:bbf7 actions=resubmit(,20)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,udp6,reg6=0x3,dl_src=fa:16:3e:7c:92:d6,dl_dst=ff:ff:ff:ff:ff:ff,tp_src=546,tp_dst=547 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,udp6,reg6=0x8,dl_src=fa:16:3e:cd:dc:f0,dl_dst=ff:ff:ff:ff:ff:ff,tp_src=546,tp_dst=547 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,udp6,reg6=0x9,dl_src=fa:16:3e:49:70:a2,dl_dst=ff:ff:ff:ff:ff:ff,tp_src=546,tp_dst=547 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,udp6,reg6=0xa,dl_src=fa:16:3e:02:02:19,dl_dst=ff:ff:ff:ff:ff:ff,tp_src=546,tp_dst=547 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=4, n_bytes=1366, priority=200,udp,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7,dl_dst=ff:ff:ff:ff:ff:ff,tp_src=68,tp_dst=67 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,udp6,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7,dl_dst=ff:ff:ff:ff:ff:ff,tp_src=546,tp_dst=547 actions=resubmit(,10)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=200,arp,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7,arp_spa=0.0.0.0,arp_op=1,arp_sha=fa:16:3e:e3:bb:f7 actions=resubmit(,20)
 cookie=0x0, table=5, n_packets=12, n_bytes=936, priority=200,icmp6,reg6=0x6,dl_src=fa:16:3e:e3:bb:f7 actions=resubmit(,20)
 cookie=0x0, table=5, n_packets=0, n_bytes=0, priority=100,ip actions=drop
 cookie=0x0, table=5, n_packets=72, n_bytes=7716, priority=100,ipv6 actions=drop
 cookie=0x0, table=5, n_packets=724, n_bytes=30408, priority=100,arp actions=drop
==============================

[gospring (gospring)]

I added external_network_bridge = br-ex in l3_agent.ini, restarted l3 agent, reset router gateway, and it worked.

[Omer Anson (omer-anson)]

In that case, would a devstack solution suffice? i.e. detect we use legacy snat or that we are a network node, and add the external_network_bridge settings to l3_agent.ini ?