On Mon, Mar 22, 2004 at 10:20:31AM -0600, 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
Perhaps there's a bug in Ethereal that causes it to claim a packet to be
a retransmission when it isn't one.
Perhaps there's a bug in the Sniffer that causes it to inject duplicate
packets into a capture.
Perhaps there's a bug in whatever tool your service provider uses to
find retransmissions that causes it *not* to claim a packet to be a
retransmission when it *is* one. (Are they using the "expert" features
of the Sniffer? If not, perhaps they should try that - I suspect it can
identify retransmissions.)
Or perhaps they're just looking at the captures to try to identify
retransmissions themselves, and not doing a sufficiently good job of it
to see them.