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r/sysadmin • … • u/BoRedSox

Ubuntu 22.04 and systemd-resolved

So I've been working on some automation to setup Ubuntu servers from a VMM template.

Has anyone run into an issues with DNS when using Ubuntu 22.04 with firewalld?

It appears that firewalld does not exempt the 127. addresses automatically.

I've found two ways to resolve one is using a symlink to bypass systemd-resolved for DNS.

Another is to allow outbound to destination address 127.0.0.53 on port 53, udp and tcp.

When looking at Ubuntu 20.04 neither of these steps appear to be required. Just can't make any sense of the difference causing this. Have researched for hours with no conclusion. Any thoughts?

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