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Neutron external network namespace unable to route to or

asked 2014-02-20 13:49:35 -0600

tzakrajs gravatar image

updated 2014-02-20 17:15:50 -0600

I have a controller node, network node and compute node all connected to a VirtualBox Bridge Network ( subnet). Additionally, they are connected to a management network The compute and network nodes are also additionally connected over a data network (for GRE)

The nodes with addresses can ping eachother just fine as well as addresses inside the br-ex (the external bridge). The problem is that nothing behind br-ex can route to, and thus instances cannot get to the internet ( The nova instances cannot ping any address that isn't connected to the VirtualBox bridge or the openvswitch external bridge. Private nova instance gateway is properly routing to, but again, not beyond the VirtualBox bridge (to the D-Link Router).

Details here:

Was I incorrect to use as my ext-net cidr since I am relying on an upstream router with the same subnet to route packets to the internet?

Example of bad behavior, from inside vm:

$ ping
PING ( 56 data bytes
--- ping statistics ---
169 packets transmitted, 0 packets received, 100% packet loss

and then from the external gateway interface connected to the br-ex bridge

root@network-1:~# ip netns exec qrouter-45389376-b5b2-4032-8203-ed82cc870ea1 tcpdump -nei qg-c947b62d-8f
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on qg-c947b62d-8f, link-type EN10MB (Ethernet), capture size 65535 bytes
15:11:17.553904 fa:16:3e:af:cf:f6 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Request who-has tell, length 28
15:11:18.550822 fa:16:3e:af:cf:f6 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Request who-has tell, length 28
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answered 2014-02-21 22:59:23 -0600

tzakrajs gravatar image

I have worked around this by setting up a nat gateway on and using it as the default gateway for the qrouter namespace.

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how do you do that exactly? i have a similar issue i think

n7rxDE gravatar imagen7rxDE ( 2014-08-27 04:01:50 -0600 )edit

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Asked: 2014-02-20 13:49:35 -0600

Seen: 2,166 times

Last updated: Feb 21 '14