[pkg-dhcp-devel] Bug#717215: dhcpd: 5 bad udp checksums in 5 packets

[Kenneth johansson]

Package: isc-dhcp-server
Version: 4.2.4-7
Severity: normal


So I run debian 7.0 in two libvirt handled virtual machines.
they both use virtio driver for network.

one is a dhcp server the other is dhcp client.

now what I see on the server is the following error on syslog.
dhcpd: 5 bad udp checksums in 5 packets

searching the web this type of problem has exists since some time in 2010 in one or another form.
What is happening is that when virtio is used the checksum is never calculated on packets that goes to from virtual machines on the same host. nor is the udp checksum set to 0 indicating that no checksum is used.


redhat has a fix for this.
http://pkgs.fedoraproject.org/cgit/dhcp.git/tree/dhcp-4.2.2-xen-checksum.patch?id=038d346d726e131f1ab2579fe015a72b49733a0d;id2=HEAD

I myself just removed the checksum check on the server since that was a simpler fix (for me, its obviously a worse fix) and that made dhcp work for me.



-- System Information:
Debian Release: 7.0
   APT prefers stable-updates
   APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.9.5 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages isc-dhcp-server depends on:
ii  debconf [debconf-2.0]  1.5.49
ii  debianutils            4.3.2
ii  isc-dhcp-common        4.2.4-7
ii  libc6                  2.13-38
ii  lsb-base               4.1+Debian8

isc-dhcp-server recommends no packages.

Versions of packages isc-dhcp-server suggests:
pn  isc-dhcp-server-ldap  <none>

-- Configuration Files:
/etc/dhcp/dhcpd.conf changed [not included]

-- debconf information excluded