Question regd timestamp option

Chuck Swiger cswiger at mac.com
Fri Aug 12 21:14:57 GMT 2005


Miku Jha wrote:
[ ... ]
> The situation is that if the client crashes, the server eventually sends a
> RST (10.39.53) Following this RST, the client comes back in lets say around
> 2-3 minutes. Now when the client sends a SYN(10.42.23), there is no 
> timestamp option.

If the client opens a connection and both sides exchange packets with 
timestamps, you'll probably end up seeing "NNT" in all packets during the first 
session.  This right?

Now if you open a second connection, while things are still OK, do you see the 
SYN packet contain all options as normal?  I assume the client is opening 
connections to the server?  And it is a FreeBSD box...?

Showing tcpdump data (or putting on a website somewhere) would help understand 
the issue...

> Is there some requirement that RST needs to be ACKED
> or RST flag will remain set for some time window
> within which if SYN is send, timestamp option will not
> be set.

A RST to a closed or listening socket will be ignored (dropped), a RST which 
matches an established connection will flush and close that connection but will 
not be ACKed itself.

-- 
-Chuck



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