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

Philipp Hahn hahn at univention.de
Wed Nov 6 19:58:53 UTC 2013

On Wed, 18 Sep 2013 14:16:08 +0200, Bastian Blank wrote:
> Why does dhcpd check the checksum, which is already done by the kernel?

dhcpd is using RAW sockets to work with Ethernet packets. (DHCP is used
to configure IP, so it has to work on a lower level than IP.)

RAW sockets bypass the kernels IP network stack (even iptbale rules!),
so the kernel never gets a chance to check the UDP checksum.
Philipp Hahn
Open Source Software Engineer

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