If you do not receive a response to a ping, or if the response is seriously delayed, you might like to take this as a warning. But who wants to ping all day? You need a ping-based monitoring utility like Smokeping.
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?