The MPLS WG Archive

[Michael Mandelberg <mmandelberg@lopsys.com>]

According to rfc 3473:

 

A node that receives an IF_ID object SHOULD

   check whether the information carried in this object is consistent

   with the information carried in a received ERO, and if not it MUST

   send a PathErr Message with the error code "Routing Error" and error

   value of "Bad Explicit Route Object" toward the sender.  This check

   CANNOT be performed when the initial ERO subobject is not the

   incoming interface.

 

However, an LSR receiving a path message with an ero processes it as follows: if the LSR is a part of the node specified by the first subobject, it selects a hop, then *removes* that subobject. In other words, the ERO does not contain information about the route to get to that LSR, this information is in the RRO.

 

This may be a minor point, but I want to make sure that I understand it properly. Shouldn't the text above say:

 

 

A node that receives an IF_ID object SHOULD

   check whether the information carried in this object is consistent

   with the information carried in a received **RRO**, and if not it MUST

   send a PathErr Message with the error code "Routing Error" and error

   value of "Bad Explicit Route Object" toward the sender.  This check

   CANNOT be performed when the initial **RRO** subobject is not the

   incoming interface.

 

Am I mistaken? If so, why?

 

Thanks

 

Michael Mandelberg