Re: TCP stack behaviour question

From: Samuel Tardieu
Date: Tue Sep 19 2006 - 08:06:33 EST


>>>>> "Stuart" == Stuart MacDonald <stuartm@xxxxxxxxxxxxxxx> writes:

Stuart> I suppose that the TCP retransmits aren't being sent because
Stuart> the ethernet and/or IP layers don't know what's going on,
Stuart> which is what's producing the arps. Is that correct?

It seems correct. You cannot expect TCP packets to be sent if the
target is supposedly on a directly connected network and ARP cannot
get its MAC address. What should the IP layer put as the MAC address
if it is unknown?

You may want to run another test with another unreachable target
located after a router, so that the MAC address of the router is used
on the wire. You should see all the TCP retransmits you expect to see.

Sam
--
Samuel Tardieu -- sam@xxxxxxxxxxx -- http://www.rfc1149.net/

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