#796558 dhcp 5 bad udp checksums in 5 packets

Package:
dnsmasq
Source:
dnsmasq
Submitter:
Daniel
Date:
2015-08-23 14:54:03 UTC
Severity:
important
#796558#5
Date:
2015-08-22 15:23:50 UTC
From:
To:
This bug is the same as closed bug #717215 but not on isc-dhcp-server but dnsmasq which mean it's not related
to a specific package.

We have a server running qemu-kvm, dnsmasq and libvirt.We have 3 VM, one Windows, one Debian 8 and one CentOS 5.
All of them are using the virtio net driver, everything is working perfect witch Debian 7 aka Wheezy.

The server was upgraded to Debian 8 aka Jessie: the Windows VM has no problem with dhcp, the 2 linux
boxes stop to get they IP address from dhcp server despite the fact that the discovery/offer is send
and received as shown with a tshark capture.

This problem seems to be an old as seen in the above named bug.A workaround was found on calico and openstack lists
which is:

iptables -t mangle -A OUTPUT -o virbr+ -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill

and/or any other bridged interface used by the system.