Hi, Robert:

 

Actually, the IGP stub link 
draft(https://datatracker.ietf.org/doc/draft-wang-lsr-stub-link-attributes/)  
starts from the ‘passive link’, then to more general concept ‘stub link’.

We still think the proposed “Stub-Link” TLV in this document for OSPF/IS-IS is 
one more valid container to convey more information about the 
stub-link(especially for the non-inter-as scenario), not solely the current 
information that are conveyed via the OSPF/IS-IS TE TLV.

 

Are you interested to forward it together?

 

Aijun

 

From: [email protected] [mailto:[email protected]] On 
Behalf Of Robert Raszuk
Sent: Wednesday, May 27, 2026 4:28 AM
To: Susan Hares <[email protected]>
Cc: Acee Lindem <[email protected]>; lsr <[email protected]>; idr-chairs 
<[email protected]>; Dongjie (Jimmy) <[email protected]>; Ketan Talaulikar 
<[email protected]>
Subject: [Lsr] Re: Request for comment on BGP-LS draft: 
draft-ietf-idr-bgpls-inter-as-topology-ext-32 - (1 Week for comment: 5/26 to 
6/1)

 

Hi Sue,

 

For tens of years we have been marking Inter-AS links in IGP as passive. 

 

Remember the times where edge nodes were not setting next hop self on 
everything ? This was the method to actually advertise in IGP the BGP next hops 
of the peer. 

 

I think you may have interpreted "passive link" as not an "active link" but 
this is completely not the case. I am using "passive" as in IGP terminology. 

 

Claude explains it like this: 

 

Passive link — an interface that the router advertises into the IGP but on 
which it does not send or process hello packets. No adjacency will ever form 
over it, even if a neighbor exists. You configure this with passive-interface 
in OSPF or by marking a circuit passive in IS-IS. The reachability gets 
advertised, but no IGP traffic crosses the link.

 

Thx,

R.  

 

On Tue, May 26, 2026 at 10:19 PM Susan Hares <[email protected] 
<mailto:[email protected]> > wrote:

Robert:

 

The draft specifies Inter-AS links (see diagram in document).   These are not 
passive links.  The links are active for inter-AS traffic, and the BGP-LS is 
helping the controller made decisions on traffic. I believe these are not 
related to the stub-links for IGP.  We are waiting for Ketan and Aijun to 
comment. 

 

Sue 

 

From: Robert Raszuk <[email protected] <mailto:[email protected]> > 
Sent: Tuesday, May 26, 2026 2:24 PM
To: Acee Lindem <[email protected] <mailto:[email protected]> >
Cc: Susan Hares <[email protected] <mailto:[email protected]> >; lsr <[email protected] 
<mailto:[email protected]> >; idr-chairs <[email protected] 
<mailto:[email protected]> >; Dongjie (Jimmy) <[email protected] 
<mailto:[email protected]> >; Ketan Talaulikar <[email protected] 
<mailto:[email protected]> >
Subject: Re: [Lsr] Re: Request for comment on BGP-LS draft: 
draft-ietf-idr-bgpls-inter-as-topology-ext-32 - (1 Week for comment: 5/26 to 
6/1)

 

 

Wouldn't passive interfaces be sufficient instead of stub-links ? 

 

Thx,

r.

 

On Tue, May 26, 2026 at 6:59 PM Acee Lindem <[email protected] 
<mailto:[email protected]> > wrote:

Hi Sue, 

> On May 26, 2026, at 12:39 PM, Susan Hares <[email protected] 
> <mailto:[email protected]> > wrote:
> 
> Acee: 
> 
> If the data comes from IGP (OSPF and ISIS), the answer is yes. 
> 
> However, section 8 allows for an Inter-AS link information from a BGP peer 
> (BGP-LS from BGP only) to set the source on the inter-AS links as either 
> static or "directly" connected.  Please review sections 8 and 9.  
> 
> Do these two sections provide enough detail to avoid the issues from the IGP 
> Stub-links draft?  

I would think so and if the information were to advertised in OSPF or IS-IS, 
the existing TE encodings would be used. 

However, this is a good question for the authors. We don't want to rehash these 
stub-links drafts under any circumstances. 

Thanks,
Acee



> 
> Sue 
> 
> 
> -----Original Message-----
> From: Acee Lindem <[email protected] <mailto:[email protected]> > 
> Sent: Tuesday, May 26, 2026 12:32 PM
> To: Susan Hares <[email protected] <mailto:[email protected]> >
> Cc: lsr <[email protected] <mailto:[email protected]> >; idr-chairs 
> <[email protected] <mailto:[email protected]> >; Dongjie (Jimmy) 
> <[email protected] <mailto:[email protected]> >; Ketan Talaulikar 
> <[email protected] <mailto:[email protected]> >
> Subject: Re: [Lsr] Request for comment on BGP-LS draft: 
> draft-ietf-idr-bgpls-inter-as-topology-ext-32 - (1 Week for comment: 5/26 to 
> 6/1)
> 
> Speaking as both WG chair and WG member: 
> 
> I don't have a problem with this draft as long as RFC 5392 (OSPF) and RFC 
> 9346 (IS-IS) are used as the source of the BGP-LS inter-AS topo information. 
> We don't have time in LSR to rehash the IGP stub-links drafts just because 
> IDR is advancing this document.
> 
> Thanks,
> Acee
> 
>> On May 26, 2026, at 8:45 AM, Susan Hares <[email protected] 
>> <mailto:[email protected]> > wrote:
>> 
>> Greetings LSR:
>> IDR has reached consensus to publish 
>> draft-ietf-idr-bgpls-inter-as-topology-ext-32.
>> This draft defines a new type within the BGP-LS Network Layer Reachability 
>> Information (NLRI) for an Inter-AS Link, as well as three new 
>> type-length-values (TLVs) for the BGP-LS Inter-AS Link descriptor.   It 
>> allows the following two types of use cases: 1) IGP (ospf or isis)  to 
>> BGP-LS and 2) BGP-only (import data from static/direct interfaces) to 
>> BGP-LS). 
>> Please respond to this message if you object to the publication of the 
>> draft.  Otherwise, the IDR chairs will forward this to the IESG for 
>> publication on 6/1/2026.
>> Cheerily, Sue Hares
>> Shepherd  
>> IDR  co-chair    _______________________________________________
>> Lsr mailing list -- [email protected] <mailto:[email protected]> 
>> To unsubscribe send an email to [email protected] 
>> <mailto:[email protected]> 
> 
> 

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