Hi there, I've updated my server to bullseye a couple of days ago and since then I'm unable to get IPv4 networking to work properly again. IPv6 still seems to work like charm. I can also connect to the hosted VMs (KVM via libvirt) on the server over IPv4 without problems. However, when I try to address the server directly, all packets seem to be dropped on the outgoing interface. If, for instance, I ping the server, I can see the ICMPv4 echo requests _and_ replies in tcpdump, but the pinging peer won't never receive the replies. If I check the ARP tables I can find the gateway's MAC address tagged as DELAY.
The general setup has worked before the dist-upgrade for years and I'm a bit clueless what might has been broken during the update. Cheers Oleg
