IDS (Intrusion Detection System) Symantec Sygate Enterprise Protection only. A device or software that detects and notifies a user or enterprise of unauthorized or anomalous access to a network or computer system. Symantec’s IDS operates on every machine in an enterprise where the Symantec Protection Agent is installed by analyzing network packets targeted at the network node and comparing them with signature database entries. An IDS helps identify attacks and probes by monitoring traffic for attack signatures that represent hostile activity. Symantec’s software includes Intrusion Protection as well as Intrusion Detection. See also Intrusion Prevention System (IPS).