Wierd combination of TCP flags in Fedora 9, iptables rule to fix

stan goedigi89__e at cox.net
Thu Jul 10 01:46:03 UTC 2008

Through a miscue I lost the iptables setup that came with Fedora 9.  I 
created a new set of rules and decided that I would restrict OUTPUT 
chains instead of allowing anything to go as the Fedora firewall does.  
I kept an eye on the logs and added services that were used.  Everything 
was working fine.  Then I decided to run a    yum update   .  

It worked but I got a lot of two kinds of TCP packets logged. 

One was SYN packets with random destination ports at the high end of the 
range.  I'm assuming this was something to do with passive FTP.  Why 
they should show up I'm not sure since I have FTP enabled and RELATED, 

The second was packets to port 80 on the repository with flags  ACK, 
PSH, FIN.  I've looked and looked but can't find why this combination is 
being sent.  Does anyone know what this is and what rule in iptables 
would take care of it?  I've come up with   "$IPTABLES -A OUTPUT -p tcp 
--dport 80 --tcp-options  SYN,ACK,PSH,FIN ACK,PSH,FIN -j ACCEPT    .  
Why wouldn't this combination be accepted as RELATED, ESTABLISHED 
already?  Or is yum/urlgrabber/tcp sending this in error so I should 
just drop it?

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