RFC 6325, "Routing Bridges (RBridges): Base Protocol Specification", July 2011

Note: This RFC has been updated by RFC 6327, RFC 6439, RFC 7172, RFC 7177, RFC 7357, RFC 7179, RFC 7180, RFC 7455, RFC 7780, RFC 7783, RFC 8139, RFC 8249, RFC 8361, RFC 8377

Errata ID: 3508
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Donald E. Eastlake, 3rd
Date Reported: 2013-03-05
Verifier Name: Ralph Droms
Date Verified: 2013-03-09

Section 4.5.1 says:

In other words, the set of potential parents for N, for the tree
rooted at R, consists of those that give equally minimal cost paths
from N to R and that have distinct IS-IS IDs, based on what is
reported in LSPs.

It should say:

In other words, the set of potential parents for N, for the tree 
rooted at R, consists of those that give equally minimal cost paths 
from R to N and that have distinct IS-IS IDs, based on what is 
reported in LSPs.

Notes:

Link costs can be asymmetric. The above erroneous sentence is inconsistent with the rest of 4.5.1 and normal practice. Furthermore, it is important to fix this and resolve the inconsistency because, if all RBridges in a TRILL campus do not compute the same trees, the reverse path forwarding check for multi-destination TRILL Data packet routing can erroneously discard such packets.

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