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canonical / lxd

Powerful system container and virtual machine manager
https://canonical.com/lxd
GNU Affero General Public License v3.0
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port 53 forwarding kept giving internal dns names #13570

Open eedgar opened 5 months ago

eedgar commented 5 months ago

Please describe the question or issue you're facing with "LXD". We were running ovn and lxd and using the port forwarding feature. It appears that there was some internal issue with dnsmasq hijacking the traffic as the reponse to the port forward leaked internal dns information incorrectly.

the issue was that lxd/ovn was setup to respond to the same domain name as we were trying to expose via a bind server that was port forwarding. The workaround was to change the lxd/ovn networking to use a different domain. However this was a very unexpected result from a simple port foward as we didnt expect dnsmasq to be involved at all.

Reported from: https://documentation.ubuntu.com/lxd/en/latest/

tomponline commented 5 months ago

Please can you show the specifics of your setup so we can investigate.

OVN does use egress DNS packet inspection and response rewriting as they traverse through the virtual router in order to resolve internal DNS names.

So perhaps this is what you observed.