Comment 22 for bug 1302080

Tore, so it looks like you're using linuxbridge, which I will admit I don't typically run. I'll try and get a config with that up and running.

FYI, I can't reproduce what you're seeing using OVS.

Config:
- Ubuntu 16.04
- single-node devstack
- neutron w/OVS configured with OVSHybridIptablesFirewallDrive
- DVR enabled

Boot a single VM

qbr bridge is created for hybrid plugging, which was where the IPv6 link-local address was being configured.

$ sysctl net.ipv6.conf.qbr74767d3d-4a.disable_ipv6
net.ipv6.conf.qbr74767d3d-4a.disable_ipv6 = 1

$ ip a s qbr74767d3d-4a
15: qbr74767d3d-4a: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UP group default qlen 1000
    link/ether ce:93:48:a0:42:c0 brd ff:ff:ff:ff:ff:ff

So there's no addresses there at all.

From inside the VM I can ping the all-nodes multicast address:

$ ping6 -I eth0 ff02::1
PING ff02::1 (ff02::1): 56 data bytes
ping6: can't bind to interface eth0: Operation not permitted
64 bytes from fe80::f816:3eff:fec0:a651: seq=0 ttl=64 time=2.408 ms
64 bytes from fe80::f816:3eff:fe92:17e9: seq=0 ttl=64 time=5.795 ms (DUP!)
64 bytes from fe80::f816:3eff:fe41:6efc: seq=0 ttl=64 time=7.924 ms (DUP!)
64 bytes from fe80::f816:3eff:fe6b:f22: seq=0 ttl=64 time=8.231 ms (DUP!)
64 bytes from fe80::f816:3eff:fe7d:2e94: seq=0 ttl=64 time=10.130 ms (DUP!)
64 bytes from fe80::f816:3eff:fe5e:b721: seq=0 ttl=64 time=10.410 ms (DUP!)

Each address is something that responded:

fe80::f816:3eff:fec0:a651 - the VM itself
fe80::f816:3eff:fe92:17e9 - dhcp server
fe80::f816:3eff:fe41:6efc - router (distributed interface - v4 subnet, it's local to the VM)
fe80::f816:3eff:fe6b:f22 - router (centralized snat interface - v4 subnet)
fe80::f816:3eff:fe7d:2e94 - router (distributed interface - v6 subnet)
fe80::f816:3eff:fe5e:b721 - router (centralized snat interface - v6 subnet)

I tried to ssh to all of those addresses from the neutron infrastructure and couldn't - connection refused.