View TCP Listeners Information

Perform this procedure to view a detailed list of systems that are in the listening state.

When a connection is in the listen state an end point system is waiting for a returning handshake (SYN).The normal listening state should be very transient, changing all of the time. Two or more systems going to a common system in an extended listening state indicates the need for further investigation. End systems in an extended listening state can indicate a broken TCP connection or a DOS attack on a resource. This type of DOS attack, known as a SYN attack, results from the transmission of SYNs with no response to return replies. While many systems can detect a SYN attack, the TCP listener statistics can provide additional forensic information.