[Virtual-pkg-base-maintainers] Bug#796558: dhcp 5 bad udp checksums in 5 packets

[Daniel]

Package: base
Severity: important

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.


-- System Information:
Debian Release: 8.1
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)