[ale] Iptables: Packets from port 80 to unestablished ports

Dow Hurst dhurst at kennesaw.edu
Wed Jul 30 10:32:11 EDT 2003


So to clarify this:

Are you saying that these web servers are sending ACKs to unrelated high 
port numbers to accelerate the response of the client?  Sending the ACK 
to a different port number than the port that would be appropriate is a 
violation of the normal TCP protocol as y'all have stated.  So it looks 
like an attack/probe to the firewall.
Dow


Jonathan Rickman wrote:

>On Tuesday 29 July 2003 21:56, Transam wrote:
>
>  
>
>>If it's Winbloz IIS, it may be violating the TCP protocol in such a way
>>that response time to a IE client is faster than not violating the TCP
>>protocol but sending to anyone else that follows the protocol is slower.
>>Also, some firewalls get upset.
>>    
>>
>
>Roxen exhibits this behavior as well. Some of the older load balancing 
>appliances tend to break things too.
>
>  
>

-- 
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Dow Hurst                  Office: 770-499-3428
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Kennesaw State University         Dow.Hurst at mindspring.com
Kennesaw, GA 30144
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