Really, you'd want to expose the pseudoheader check at endhosts; a well-instrumented Linux box could tell you a lot about checksum failures. But in this case, a router would be decapping UDP/MPLS tunnels as an endpoint, so could report on checksum failures - if the checksum wasn't zero. Lloyd Wood http://about.me/lloydwood ________________________________________ From: Dino Farinacci [farinacci@xxxxxxxxx] Sent: 12 January 2014 21:37 To: Wood L Dr (Electronic Eng) Cc: <mark.tinka@xxxxxxxxx>; <mpls@xxxxxxxx>; gorry@xxxxxxxxxxxxxx; lisp@xxxxxxxx; david.black@xxxxxxx; randy@xxxxxxx; tsvwg@xxxxxxxx; jnc@xxxxxxx; ietf@xxxxxxxx Subject: Re: [lisp] [mpls] draft-ietf-mpls-in-udp was RE: gre-in-udp draft (was: RE: [tsvwg] Milestones changed for tsvwg WG) > Do any routers count TCP/UDP checksum failures, much less > expose the count via SNMP? Typically they do but only for packets destined to them. Much like hosts would check the header checksum. Dino