The Generalized TTL Security Mechanism (GTSM) for Label Distribution Protocol (LDP)
Cisco Systems
Cisco Systems
The Generalized TTL Security Mechanism (GTSM) describes a generalized use of a packets Time to Live (TTL) (IPv4) or Hop Limit (IPv6) to verify that the packet was sourced by a node on a connected link, thereby protecting the router's IP control-plane from CPU utilization based attacks. This technique improves security and is used by many protocols. This document defines the GTSM use for Label Distribution Protocol (LDP).