Refusing Pings on Core Routers??? A new trend?

Patrick W. Gilmore patrick at
Fri Oct 20 02:19:48 UTC 2006

On Oct 19, 2006, at 10:14 PM, Rubens Kuhl Jr. wrote:
>> template response -- I hear is "Well, you can't rely on traceroute
>> because of ICMP prioritisation".  When you start to explain how
>> traceroute actually works (both ICMP-based and UDP-based (which
>> still relies on ICMP responses, of course!)), and that ICMP prio
>> should only affect the IP of which the router listens on (and not
>> hops beyond or at the dest), most NOCs fire back with another
> If I recall well, Cisco GSRs impose low priority and/or limits for all
> ICMP traffic flowing thru the box, not just packets to/from router
> itself, and there's not a knob to adjust that.

You don't recall well.

Although there is a knob if you want to tweak it.  But there's a knob  
for just about everything - it's just not tweaked by default.


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