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SYN/RST-Only Packet Sources

The SYN/RST-Only Packet Sources sensor looks for hosts that send out unusually large amounts of SYN-RST packets. This behavior may indicate a SYN or RST flood.

Troubleshooting an SYN/RST-Only Packet Sources Alert

An alert from the SYN/RST-Only Packet Sources sensor may indicate that someone is attempting to hack into the network. Specifically, SYN-RST packets are associated with attempts to bypass a firewall perimeter.

SYN/RST-only packet flows signal a connection establishment request that is immediately followed by a reset request, which is not characteristic of normal TCP behavior. This behavior typically indicates scanning activity, which may include OS fingerprinting.