Editing Transmission Control Protocol (section)

==Debugging==
A [[packet sniffer]], which [[Network tap|taps]] TCP traffic on a network link, can be useful in debugging networks, network stacks, and applications that use TCP by showing an engineer what packets are passing through a link. Some networking stacks support the SO_DEBUG socket option, which can be enabled on the socket using setsockopt. That option dumps all the packets, TCP states, and events on that socket, which is helpful in debugging. [[Netstat]] is another utility that can be used for debugging.