[neutron] exposing ip address of external Network from

Slawek Kaplonski skaplons at redhat.com
Fri Apr 8 05:52:29 UTC 2022


On czwartek, 7 kwietnia 2022 17:04:26 CEST A Monster wrote:
> When I attach an interface to an external network, openstack gives an ip
> address of to the instance,
> Inside the instance, I can see a new network interface, but it doesn't get
> an ip address automatically, and when I configure it to have
> manually, I still cannot ping the other ips on this network, and I cannot
> ping from the outside
> I think it's not feasible to attach instances to external networks.

External network in Neutron is the same L2 network as any other. The only difference is that such network is marked as "external" so neutron knows that can use floating Ips from it and use that network as router's gateway. 
Plugging instance into such network is totally valid and should works.
Maybe Your external network have disabled dhcp and that's why VM don't get IP address automatically.
Please check first if You configured proper netmask manually. Then please check step by step where Your packets are dropped. Maybe http://kaplonski.pl/blog/neutron-where-is-my-packet-2/[1] will be somehow helpful for You. This is mostly about vxlan (tenant) network but there is flat network used for router gateway there and traffic from your vm should go the same path as traffic from the router's gateway in that post.

Slawek Kaplonski
Principal Software Engineer
Red Hat

[1] http://kaplonski.pl/blog/neutron-where-is-my-packet-2/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-discuss/attachments/20220408/4f4c3ef7/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.openstack.org/pipermail/openstack-discuss/attachments/20220408/4f4c3ef7/attachment.sig>

More information about the openstack-discuss mailing list