Status:

Verified

Type:

Technical

Reported By:

Donald E. Eastlake, 3rd

Date Reported:

2013-03-05

Verified by:

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.