Speaking as WG member: Hi Li,
> On Mar 3, 2026, at 8:36 AM, zhangli (CE) <[email protected]> wrote: > > Hi Tony and Acee, > > Thanks a lot for your valuable comments and insights. > > Tony's understanding is right, it is based on the case where someone has > multiple VLANs over one link between two routers. As Acee mentioned, there > are many cases that a router establishes several links with another router by > several sub-interfaces in the practical network deployment. But much less so for IS-IS since there can only be a L1 and L2 area and there is already the concept of a L1-L2 adjacency. > However, a sub-interface does not have its own independent bandwidth and > utilization information, its bandwidth and utilization information is just > copied from their parent physical interface. > > When a remote device want to do load balancing based on the available > bandwidth information, it can not know that several links are sharing the > same physical bandwidth. This may lead to an unbalanced load, even result in > packet loss when the traffic on a physical interface exceeds it max bandwidth. > > Therefore, this document propose extensions to IGP to advertise the > relationship between a physical interface and its sub-interfaces. This > information is valuable for load balancing in the head end. Also, IS-IS already has https://datatracker.ietf.org/doc/html/rfc5307#section-1.1 and this should be enough to know if there are multiple IS-IS interfaces associated with the same physical interface. Why did you propose all this hierarchical encoding??? Thanks, Acee > > > Best regards > Li >> -----邮件原件----- >> 发件人: Acee Lindem <[email protected]> >> 发送时间: 2026年3月2日 20:28 >> 收件人: Tony Li <[email protected]> >> 抄送: zhangli (CE) <[email protected]>; lsr <[email protected]>; >> [email protected] >> 主题: Re: [Lsr] New Version Notification for >> draft-zl-lsr-igp-sub-interface-relationship-00.txt >> >> Hi Zhang, Tony, >> >>> On Mar 2, 2026, at 2:10 AM, Tony Li <[email protected]> wrote: >>> >>> >>> Hi Zhang Li, >>> >>> Perhaps I’m not understanding the problem that you’re trying to solve. >>> It seems to me that what you’re suggesting is that we create a special >>> encoding to handle the case where someone has multiple VLANs over one >>> link between two routers. Is that correct? Why would anyone want to >>> do that? I >> >> This is a common way to include an interface in multiple areas in OSPFv2. I >> expect it is used in OSPFv3 as well since people don't know how to configure >> different Instance IDs. >> >> >>> dislike adding hair to the protocol over a situation that should not exist. >> >> I haven't read the draft but I don't see why it makes any difference to the >> IGPs >> and agree. >> >> Thanks, >> Acee >> >> >>> >>> Regards, >>> Tony >>> >>> >>>> On Mar 1, 2026, at 6:56 PM, zhangli (CE) - zhangli344=40huawei.com at >> dmarc.ietf.org <[email protected]> wrote: >>>> >>>> Dear all, >>>> >>>> A new document draft-zl-lsr-igp-sub-interface-relationship-00 has been >> submitted. This draft introduces extensions to IGP, allowing a network >> device to >> advertise the relationship between a physical interface and its >> sub-interfaces. >> These extensions enable the links based on sub-interfaces to participate in >> the >> alternative paths for load balancing. >>>> >>>> Links for the draft is as below. >>>> >>>> https://datatracker.ietf.org/doc/draft-zl-lsr-igp-sub-interface-relat >>>> ionship/ >>>> >>>> Looking forward to your review and comments. >>>> >>>> Best regards >>>> Li >>>> -----邮件原件----- >>>> 发件人: [email protected] <[email protected]> >>>> 发送时间: 2026年2月28日 17:12 >>>> 收件人: lichenxi (A) <[email protected]>; Dongjie (Jimmy) >>>> <[email protected]>; zhangli (CE) <[email protected]> >>>> 主题: New Version Notification for >>>> draft-zl-lsr-igp-sub-interface-relationship-00.txt >>>> >>>> A new version of Internet-Draft >>>> draft-zl-lsr-igp-sub-interface-relationship-00.txt has been successfully >> submitted by Li Zhang and posted to the IETF repository. >>>> >>>> Name: draft-zl-lsr-igp-sub-interface-relationship >>>> Revision: 00 >>>> Title: IGP Extensions for Sub-interface Relationship Information >>>> Date: 2026-02-28 >>>> Group: Individual Submission >>>> Pages: 8 >>>> URL: >> https://www.ietf.org/archive/id/draft-zl-lsr-igp-sub-interface-relationship-00.txt >>>> Status: >> https://datatracker.ietf.org/doc/draft-zl-lsr-igp-sub-interface-relationship/ >>>> HTML: >> https://www.ietf.org/archive/id/draft-zl-lsr-igp-sub-interface-relationship-00.ht >> ml >>>> HTMLized: >>>> https://datatracker.ietf.org/doc/html/draft-zl-lsr-igp-sub-interface- >>>> relationship >>>> >>>> >>>> Abstract: >>>> >>>> This document extends ISIS and OSPF, allowing a network device to >>>> advertise the relationship between a physical interface and its sub- >>>> interfaces. This extension enables the links based on sub-interfaces >>>> to participate in the alternative paths for load balancing in SRv6 BE >>>> bandwidth polling. >>>> >>>> >>>> >>>> The IETF Secretariat >>>> >>>> >>>> _______________________________________________ >>>> Lsr mailing list -- [email protected] >>>> To unsubscribe send an email to [email protected] >>> >>> _______________________________________________ >>> Lsr mailing list -- [email protected] >>> To unsubscribe send an email to [email protected] > _______________________________________________ Lsr mailing list -- [email protected] To unsubscribe send an email to [email protected]
