Re: [Idr] Opsdir early review of draft-ietf-idr-bgp-ls-segment-routing-ext-06

"Les Ginsberg (ginsberg)" <ginsberg@cisco.com> Wed, 09 May 2018 14:35 UTC

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From: "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>
To: "Ketan Talaulikar (ketant)" <ketant@cisco.com>, Joel Jaeggli <joelja@bogus.com>, "ops-dir@ietf.org" <ops-dir@ietf.org>
CC: "idr@ietf.org" <idr@ietf.org>, "ietf@ietf.org" <ietf@ietf.org>, "draft-ietf-idr-bgp-ls-segment-routing-ext.all@ietf.org" <draft-ietf-idr-bgp-ls-segment-routing-ext.all@ietf.org>
Thread-Topic: Opsdir early review of draft-ietf-idr-bgp-ls-segment-routing-ext-06
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Date: Wed, 09 May 2018 14:35:31 +0000
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Subject: Re: [Idr] Opsdir early review of draft-ietf-idr-bgp-ls-segment-routing-ext-06
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> 2.3.3.  Source Router Identifier (Source Router-ID) TLV
> 
>    The Source Router-ID TLV contains the IPv4 or IPv6 Router-ID of the
>    originator of the Prefix.  For IS-IS protocol this is as defined in
>    [RFC7794].  The Source Router-ID TLV may be used to carry the OSPF
>    Router-ID of the prefix originator.
> 
>    The Source Router-ID TLV has the following format:
> 
>     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               |            Length             |
>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>    //                  IPv4/IPv6 Address (Router-ID)              //
>    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> 
>    where:
> 
>       Type: TBD, see Section 4.
> 
>       Length: 4 or 16.
> 
>       IPv4/IPv6 Address: 4 octet IPv4 address or 16 octet IPv6 address.
> 
>    The semantic of the Source Router-ID TLV is defined in [RFC7794].
> 
> * While RFC7794 Router-IDs are in fact IP addresses. OSPF Router-IDs are not
> even if they happen to look like them, this is particularly germain with ospfv3
> but it’s worth making the distinction.
> [KT] Agree. I would say "The semantic of the Source Router-ID TLV for ISIS is
> defined in [RFC7794]. For OSPF, the TLV carries the OSPF Router-ID of the
> originator of the prefix."

[Les:] Joel - your statement is technically correct - but Ketan's suggested text revision is repeating text that is present in the first paragraph of the section.

Since the point being made is in regards to the semantics of the value field would this be more clearly dealt with by  replacing

//                  IPv4/IPv6 Address (Router-ID)              //

With 

//       4 or 16 octet Router-ID     //

??

   Les