[c-nsp] RE: ping with a datagram size above 1500 not working

[Stephen J. Wilcox]

you can debug ip packet if you want to look closely

you can also do a tcpdump from the host that is sending the ping

icmp and ip are documented in the rfcs, i'd suggest you read through the packet 
format info if you want to see how they look.. one thing you might see different 
is if DF is set, so thats something to watch for

Steve

On Sat, 21 Jan 2006, kerwin mendes wrote:

> Also i want to know what is it that determines when a icmp packet can gp
> beyond 1500 and when not ?
> 
> cheers
> 
> > -----Original Message-----
> > From: kerwinm at inbox.com
> > Sent: Sat, 21 Jan 2006 02:49:03 -0800
> > To: cisco-nsp at puck.nether.net
> > Subject: ping with a datagram size above 1500 not working
> > 
> > Hi All
> > 
> > I got a couple of 3500 switches now on a few of them i can ping with a
> > datagram size above 1501 whereas on the others above 1500 it wont ping ,
> > its just drops the packets.
> > There is no ICMP blocking and the system mtu of these boxes are 1546.
> > 
> > Any suggestion how to check on the switch whether deframentation is
> > happening or not?
> > 
> > cheers...
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