It is quite easy to take a TCP connection down using a RST attack, and this risk increases with applications that need long-term connections, such as VPNs, DNS zone transfers, and BGP. We’ll describe how a TCP attack can happen, and we’ll show you some simple techniques for protecting your network.

Corporate policies prohibit the unauthorized connection of hardware to the company network, threatening dire consequences in the case of non-compliance. Fair enough, but how do you actually go about catching somebody trying to plug an illegal laptop into your Ethernet?

No Connection Thank you for the comments in the September 2006 Linux Magazine regarding my IBM R50e laptop. I h......
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A touchy LAN that plays like a movie diva can spoil any admin’s day. Ethtool to the rescue!

If you need a tool for filtering protocols that doesn’t depend on the port, try L7, an IPTables patch that operates through regular expressions.