Ballot for draft-ietf-lsr-l2-bundle-member-remote-id

Discuss

Mohamed Boucadair

Yes

Gunter Van de Velde

No Objection

Roman Danyliw

Recuse

Ketan Talaulikar

No Record

Andy Newton
Charles Eckel
Christopher Inacio
Deb Cooley
Éric Vyncke
Gorry Fairhurst
Jim Guichard
Mahesh Jethanandani
Mike Bishop

Summary: Has a DISCUSS. Needs 6 more YES or NO OBJECTION positions to pass.

Mohamed Boucadair
Discuss
Discuss (2026-10-16) Sent
Hi Liyan, Changwang, Xiaolong, Les, and Peter,

Thank you for the effort put into this specification. 

Special thanks for having such a clear recommended default value (MUST be disabled) for these extensions.

Please find below some few points for discussion:

# What is the exact problem to be solved?

The text has this brief sentence:

CURRENT:
   If the
   remote interface identifier could be advertised for each member link,
   the pairing relationships between the local and remote interfaces
   would be clear.

Moreover, the information about remote ids can be retrieved directly from the nodes themselves. Mirroring that information in IGP may or may not be needed, operationally.

I suggest to make the problem space clear enough that this is about allowing BGP-LS to convey such information rather than using a management system to do the correlation. Can you please add some text among those lines?

# Coupling Local/Remote id TLVs

Focusing only the normative behavior (i.e., starting from Section 4), we do have for example:

CURRENT:
   It can be carried as a sub-TLV of the OSPF L2 Bundle Member
   Attributes sub-TLV [RFC9356].
   …
   It can be carried as a sub-TLV of the BGP-LS L2 Bundle Member
   Attributes TLV [RFC9085].  

 Unless you have a case where sending a remove id without being coupled with a local id makes sense operationally, I suggest to have some text about expected behavior when only the remote ids are received, but not local id TLVs.

# Impact on correlation with local-ids

   A remote
   interface ID with value of zero MUST be ignored and handled as if the
   value was unknown.

If this is ignore before correlating with local-ids, this may get things messy. Please make it clear this must be done only after coupling local/remote ids.

# Mirroring constraint 

CURRENT:
   The remote interface identifier advertised by a router for a bundle
   member MUST be the exact non-zero 32-bit value that the neighboring
   router advertises as the L2 Bundle Member Link Local Identifier for
   that same bundle member.  

I interpret this MUST (and wording) as it forbids a node to advertize a remote-id if it didn’t revive a local-id from a peer. Is this intended?

# BGP-LS is required to implement the BGP-LS Extension 

CURRENT:
12.2.  Informative References

   …

   [RFC9552]  Talaulikar, K., Ed., "Distribution of Link-State and
              Traffic Engineering Information Using BGP", RFC 9552,
              DOI 10.17487/RFC9552, December 2023,
              <https://www.rfc-editor.org/info/rfc9552>.

Please move this one to normative
Comment (2026-10-16) Sent
# Say the obvious

OLD:
   A remote interface ID with value of zero is not valid and MUST be
   ignored and handled as if the sub-TLV was not present.  

NEW:
   A remote interface ID with value of zero is not valid and MUST be
   ignored and handled as if the sub-TLV was not present by a receiver.  

# Check

CURRENT:
   MUST NOT advertise a value of zero for the Remote Interface ID, since
   a value of zero is reserved to indicate that the remote interface
   identifier is unknown, consistent with the Link Local Identifier
   defined in [RFC4202] (see Section 7).

I failed to find which part of 4202 you were referring to.

Shouldn’t this be rfc5307#section-1.1 where we have:

   If
   the Link Remote Identifier is unknown, it is set to 0.

# Clarity

OLD:
    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type (TBA)  |     Length    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     Remote Interface ID 1                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   ~                     ...                                       ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     Remote Interface ID N                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

NEW:
    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type (TBA)  |     Length    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     Remote Interface ID 1                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   ~                     ...                                       ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     Remote Interface ID N                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

# Ordering preference

CURRENT:
   The number of Remote Interface IDs carried in this sub-TLV MUST equal
   the Number of L2 Bundle Member Descriptors advertised in the
   enclosing L2 Bundle Attribute Descriptor.  

Wonder whether it is better to recommend local ids sub-TLV to appear first.

Cheers,
Med
Gunter Van de Velde
Yes
Roman Danyliw
No Objection
Comment (2026-10-16) Sent
Thank you to Behcet Sarikaya for the GENART review.

** For the responsible AD and WG chairs: On whether this document is in-scope for the charter -- This topic of this document doesn’t appear to be in the scope of the 5 points in the charter related to maintenance.  It could be covered by “The LSR Working Group will generally manage its specific work items by milestones agreed with the responsible Area Director” but there is no milestone for this document.
Ketan Talaulikar
Recuse
Comment (2026-10-15) Not sent
I was a co-author and now a contributor on this document.
Andy Newton
No Record
Charles Eckel
No Record
Christopher Inacio
No Record
Deb Cooley
No Record
Éric Vyncke
No Record
Gorry Fairhurst
No Record
Jim Guichard
No Record
Mahesh Jethanandani
No Record
Mike Bishop
No Record