[144730] in North American Network Operators' Group
Re: Traceroute losses through NYC1.gblx.net?
daemon@ATHENA.MIT.EDU (Joel jaeggli)
Sat Sep 17 16:23:29 2011
Date: Sat, 17 Sep 2011 13:21:40 -0700
From: Joel jaeggli <joelja@bogus.com>
To: Steve Bohrer <skbohrer@simons-rock.edu>
In-Reply-To: <CE188505-3E93-4F9E-94E2-C65EA0B7C7B7@simons-rock.edu>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 9/16/11 11:42 , Steve Bohrer wrote:
> My general question is "what meaning do I give to lossy traceroutes,
> even when pings show no problem."
>
> Can I expect that backbone routers should never give me timeouts on a
> traceroute through them, so, lots of asterisks from these systems
> indicate a packet loss problem that needs to be fixed?
generation of icmp exceptions e.g. ttl exceeded can/is delberately rate
limited, such traffic is sent up to the control plane. if a router is
passing traffic loss free through the forwarding plane then you can
conclude that it's loss free through the forwarding plane.
> Or, are these traceroute asterisks essentially meaningless, and should
> be expected on any busy link?
more like it's not trivial to conclude what they mean.
