Technical Summary
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 the Label
Distribution Protocol (LDP).
This specification uses a bit reserved in RFC 5036 and therefore
updates RFC 5036.
Working Group Summary
This document has been through a pretty normal working group
process, with no discontent and strong support.
The document was last called in the MPLS working group, and information
about this last call was copied to the rtgwg.
Document Quality
We know of plans to implement this specification. A request was
sent to the MPLS working mailing list for further information and
there were indications from vendors that this will be implemnted.
Since this is based on RFC 5082 and LDP is a pretty
straightforward protocol the review process has not led to
any major changes in the document. One of the co-authors of
this document is also a co-author of RFC 5082. LDP was also
highlighted in RFC 5082 as one of the potential protocols that
the would benefite from a GTSM mechanis.
The AD review prior to IETF last call led to a number of minor
updates, and a Routing Directorate review by Eric Gray during
IETF last call led to a further revision.
Personnel
Loa Andersson (loa@pi.nu) is the document shepherd
Adrian Farrel (adrian@olddog.co.uk) is the Responsible AD