I once used a combination of ethereal, mtr and multiple
repeating wget loops to track the problem to a specific
overloaded router hop.  It's a bit hairy, but it is doable.
Ian Schorr wrote:
.....
Use this technique to prove to them - try to arrange to have captures 
taken simultaneously on both sides of the link that you suspect is 
faulty.  Find a retransmission event, and figure out what happened - was 
the packet actually "lost" on the link?  If so, you should be able to 
find the original copy of a retransmitted segment sent out to the SP's 
link AS WELL as the retransmitted segment (and in such a trace even 
Sniffer *should* find the retransmission), but when you look at the 
trace on the other side of the link, that original segment should be 
gone.  Ask them where the packet went?
Ian
Chula Bandara wrote:
Hi i am using  Etereal Version 0.10.0a and this was very useful to me 
solving connectivity issues with our Service Providers. Few days back 
i had a similar problem that i see TCP retransmission but one of my 
Service Provider did not those retransmissions. My SP was using 
Network Associates Sniffer Pro Version 4.50.04. and i got some of  
captured files from the Sniffer. Surprisingly when i open those files 
with Ethereal , it sees Retransmissions , Packet Losses , Duplicate 
ACks etc..
could this be a bug in Ethereal or the Sniffer
thanks you in advance.
cbandara
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Stephen Samuel +1(604)876-0426                samuel@xxxxxxxxxxx
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