Right, which is probably why routers today can count badly
checksum'ed Ethernet frames, but don't have the equivalent
for MPLS.
If Ethernet frames keep failing the check, you know you
have a local problem that needs fixing. That's why it's
instrumented.
Do any routers count TCP/UDP checksum failures, much less
expose the count via SNMP?
Lloyd Wood
http://about.me/lloydwood
________________________________________
From: Mark Tinka [mark(_dot_)tinka(_at_)seacom(_dot_)mu]
Sent: 12 January 2014 12:26
To: mpls(_at_)ietf(_dot_)org
Cc: Wood L Dr (Electronic Eng); adrian(_at_)olddog(_dot_)co(_dot_)uk;
randy(_at_)psg(_dot_)com; gorry(_at_)erg(_dot_)abdn(_dot_)ac(_dot_)uk;
lisp(_at_)ietf(_dot_)org; ietf(_at_)ietf(_dot_)org;
david(_dot_)black(_at_)emc(_dot_)com; jnc(_at_)mit(_dot_)edu;
tsvwg(_at_)ietf(_dot_)org
Subject: Re: [mpls] draft-ietf-mpls-in-udp was RE: gre-in-udp draft (was: RE:
[tsvwg] Milestones changed for tsvwg WG)
On Sunday, January 12, 2014 04:59:41 AM
l(_dot_)wood(_at_)surrey(_dot_)ac(_dot_)uk
wrote:
The MPLS assumption is that it's protected and checked by
a strong link CRC like Ethernet, and checked/regenerated
by stack processing between hops; here, in a path
context, with zero UDP checksums MPLS has no checking at
all.
Right, which is probably why routers today can count badly
checksum'ed Ethernet frames, but don't have the equivalent
for MPLS.
I'm sorry, when was MPLS cheap?
Current-generation ASIC's have no problem forwarding MPLS
frames at wire rate. One could go so far as to say that MPLS
has allowed vendors to make cheaper line cards also because
IP FIB's and traffic queues can be scaled down dramatically
(not that I'd every buy such line cards, but...).
Mark.