Not able to reproduce I could see the arp table update on the router namespaces on both nodes.
I tried to modify the ports on both the subnet 10.2.0.X and 10.0.0.X.
In this example I have change the 10.2.0.4 to 10.2.0.25 and 10.0.0.8 10.0.0.20. In both cases I saw that the arp entry was updated.
There is one thing that is true on both our testing is, the VM is not able to get the new IP until I reboot the VM. ( This might be filed as a different bug in nova)
ARP output from Node 2:
root@ubuntu-new-compute:~/devstack# arp -a
? (10.2.0.4) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.6) at fa:16:3e:7a:78:fe [ether] PERM on qr-66c29926-29
? (10.2.0.3) at fa:16:3e:b6:19:da [ether] PERM on qr-b25bad4f-5f
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-66c29926-29
? (10.0.0.6) at fa:16:3e:7a:78:fe [ether] PERM on qr-b2b8c9a4-68
? (10.2.0.25) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f ( changed arp info)
? (10.0.0.7) at fa:16:3e:5d:12:fd [ether] PERM on qr-66c29926-29
? (10.2.0.2) at fa:16:3e:b6:84:91 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.8) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29
? (10.0.0.8) at fa:16:3e:a1:cc:87 [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.20) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29 ( changed arp info)
? (10.0.0.7) at fa:16:3e:5d:12:fd [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.3) at fa:16:3e:fd:a1:d6 [ether] PERM on qr-66c29926-29
root@ubuntu-new-compute:~/devstack#
ARP Info from Node 1:
root@ubuntu-ctlr:~/devstack# arp -a
? (10.0.0.3) at fa:16:3e:fd:a1:d6 [ether] PERM on qr-66c29926-29
? (10.2.0.3) at fa:16:3e:b6:19:da [ether] PERM on qr-b25bad4f-5f
? (10.0.0.7) at fa:16:3e:5d:12:fd [ether] PERM on qr-66c29926-29
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-66c29926-29
? (10.2.0.4) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.6) at fa:16:3e:7a:78:fe [ether] PERM on qr-66c29926-29
? (10.2.0.25) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f
? (10.2.0.5) at <incomplete> on qr-b25bad4f-5f
? (10.0.0.5) at <incomplete> on qr-66c29926-29
? (10.0.0.20) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29
? (10.0.0.8) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29
? (10.2.0.2) at fa:16:3e:b6:84:91 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.4) at <incomplete> on qr-66c29926-29
root@ubuntu-ctlr:~/devstack#
Not able to reproduce I could see the arp table update on the router namespaces on both nodes.
I tried to modify the ports on both the subnet 10.2.0.X and 10.0.0.X.
In this example I have change the 10.2.0.4 to 10.2.0.25 and 10.0.0.8 10.0.0.20. In both cases I saw that the arp entry was updated.
There is one thing that is true on both our testing is, the VM is not able to get the new IP until I reboot the VM. ( This might be filed as a different bug in nova)
ARP output from Node 2: new-compute: ~/devstack# arp -a new-compute: ~/devstack#
root@ubuntu-
? (10.2.0.4) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.6) at fa:16:3e:7a:78:fe [ether] PERM on qr-66c29926-29
? (10.2.0.3) at fa:16:3e:b6:19:da [ether] PERM on qr-b25bad4f-5f
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-66c29926-29
? (10.0.0.6) at fa:16:3e:7a:78:fe [ether] PERM on qr-b2b8c9a4-68
? (10.2.0.25) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f ( changed arp info)
? (10.0.0.7) at fa:16:3e:5d:12:fd [ether] PERM on qr-66c29926-29
? (10.2.0.2) at fa:16:3e:b6:84:91 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.8) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29
? (10.0.0.8) at fa:16:3e:a1:cc:87 [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.20) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29 ( changed arp info)
? (10.0.0.7) at fa:16:3e:5d:12:fd [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.3) at fa:16:3e:fd:a1:d6 [ether] PERM on qr-66c29926-29
root@ubuntu-
ARP Info from Node 1: ctlr:~/ devstack# arp -a ctlr:~/ devstack#
root@ubuntu-
? (10.0.0.3) at fa:16:3e:fd:a1:d6 [ether] PERM on qr-66c29926-29
? (10.2.0.3) at fa:16:3e:b6:19:da [ether] PERM on qr-b25bad4f-5f
? (10.0.0.7) at fa:16:3e:5d:12:fd [ether] PERM on qr-66c29926-29
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-b2b8c9a4-68
? (10.0.0.2) at fa:16:3e:91:1a:d2 [ether] PERM on qr-66c29926-29
? (10.2.0.4) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.6) at fa:16:3e:7a:78:fe [ether] PERM on qr-66c29926-29
? (10.2.0.25) at fa:16:3e:7e:0b:48 [ether] PERM on qr-b25bad4f-5f
? (10.2.0.5) at <incomplete> on qr-b25bad4f-5f
? (10.0.0.5) at <incomplete> on qr-66c29926-29
? (10.0.0.20) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29
? (10.0.0.8) at fa:16:3e:a1:cc:87 [ether] PERM on qr-66c29926-29
? (10.2.0.2) at fa:16:3e:b6:84:91 [ether] PERM on qr-b25bad4f-5f
? (10.0.0.4) at <incomplete> on qr-66c29926-29
root@ubuntu-