Dave and David,
Hope you can help me to figure out the following issues with
regard to “draft-ietf-bfd-multihop-8”:
- Multiple BFD sessions between
one pair of system was mentioned several times in the document. Is the
purpose of having multiple BFD sessions between the same pair for
traversing different alternative routes between the same pair? If yes, the
document didn’t say how to enforce it. Even the different
Destination/Source addresses being used can’t guarantee that those
BFD sessions will traverse different paths. Is it out of the scope of this
document?
- What are the benefits of
enforcing BFD sessions between a pair of nodes to traverse alternative
paths between them? I guess by doing so, the two nodes get to know how
many different paths are between them. Who will use this information?
- Your BFD base draft
(draft-ietf-bfd-base-09) does state that one of the goals of BFD is to
traverse all possible paths between two nodes. Does it include the
alternative paths between specific Ingress and Egress?
- Suggestion if you do think it
is necessary to traverse all the alternative paths between two nodes as
indicated in the BFD base document:
- Is it possible to create a
special BFD session that all intermediate nodes will forward the BFD to
all the paths in the ECMP group? Whenever it happens, the node will mark
a bit to the Discriminator field. By receiving all the BFD frames with
different Discriminator value, the egress node can figure out how many
alternative paths are between them.
Hope to have more discussion in Hiroshima.
Linda Dunbar
Advanced Technology Dept, Wireline
Networks,
Huawei Technologies, Inc.
