RFC 5310, "IS-IS Generic Cryptographic Authentication", February 2009Source of RFC: isis (rtg)
Errata ID: 2461
Publication Format(s) : TEXT
Reported By: Tony Li
Date Reported: 2010-08-12
Rejected by: Adrian Farrel
Date Rejected: 2012-08-16
Section 3.4 says:
The authentication data for the IS-IS IIH PDUs MUST be computed after the IS-IS Hello (IIH) has been padded to the MTU size, if padding is not explicitly disabled.
It should say:
The authentication data for the IS-IS IIH PDUs MUST be computed after the IS-IS Hello (IIH) has been padded to the MTU size, if padding is not explicitly disabled. ISes (routers) that implement CRYPTO_AUTH authentication and initiate LSP purges MUST remove the body of the LSP and add the authentication TLV.
The RFC ignores the case of when an IS initiates a purge. Purges MUST be authenticated explicitly, otherwise the default protocol machinery will leave open a trivial attack.
This issue appears to be correct, but does not qualify as something that can be addressed through the Errata System because it is a functional change to the document, not a typo. If the WG feels that it needs to be addressed, this should be captured in a new I-D.