On (2014-01-13 14:11 -0500), Curtis Villamizar wrote:
One of the reasons that IPv6 (rfc2460) dropped the header checksum
that was in IPv4 is that with link layers all doing FCS it served no
purpose. For the same reason TCP and UDP checksums server no purpose.
One datapoint from today. Peering router has 4xLACP to core and in one of
these LACP members it is sometimes mangling packets during send and FCS is
being calculated for this mangled data.
All egress PE boxes start logging errors (maybe 1 error per 30min), because
they check IP checksum, which is now incorrect.
Router is latest generation service provider router from major vendor running
recent software and affected router is logging no errors. Can't imagine when,
if ever, would this issue have been found without IP checksums.
--
++ytti