Right, so all the hosts I use already have this in "sudo iptables -L -t mangle"
Chain POSTROUTING (policy ACCEPT) target prot opt source destination CHECKSUM udp -- anywhere anywhere udp dpt:bootpc CHECKSUM fill I suspect this is added in some way by libvirt (which I have installed on all of them). Manually this would be done by: sudo iptables -A POSTROUTING -t mangle -p udp --dport bootpc -j CHECKSUM --checksum-fill -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/930962 Title: dhcp3-server reports many bad udp checksums to syslog using virtio NIC To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/930962/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs