Re: [Teas] Éric Vyncke's No Objection on draft-ietf-lsr-isis-rfc5316bis-04: (with COMMENT)

["Eric Vyncke (evyncke)" <[e-mail]>]

John

Thanks for your reply, it made me dig further... and I am afraid that I mixed up OSPF and IS-IS... (hey, I am just an INT AD ;-) )

I.e., AFAIK the router ID in OSPF is indeed a 32-bit value that must be unique (and is often simply an IPv4 address) used in LSA; while in the TE case, the router I-D is *NOT* is not really identifying the router for normal IS-IS computation but is 'only' a TLV for traffic engineering...

Let's put my mix-up on being Friday ;-)

Authors, if the above is correct, then please ignore my comments on section 3.1.

Regards

-éric


On 16/09/2022, 15:13, "John Scudder" <[e-mail]> wrote:

    Hi Éric,

    A few comments below.

    > On Sep 16, 2022, at 4:27 AM, Éric Vyncke via Datatracker <[e-mail]> wrote:
    > 
    > ## COMMENTS
    > 
    > ### Section 3.1
    > 
    > ```
    >   The Router ID field of the inter-AS reachability TLV is 4 octets in
    >   length, which contains the IPv4 Router ID of the router who generates
    >   the inter-AS reachability TLV.  The Router ID SHOULD be identical to
    >   the value advertised in the Traffic Engineering Router ID TLV
    >   [RFC5305].  If no Traffic Engineering Router ID is assigned, the
    >   Router ID SHOULD be identical to an IP Interface Address [RFC1195]
    >   advertised by the originating IS.
    > ```
    > 
    > AFAIK, the router ID is 'just' a 32-bit value that it is protocol version
    > agnostic. So, s/IPv4 Router ID/Router ID/ ?
    > 
    > Suggest: s/IP Interface Address [RFC1195]/IPv4 Interface Address [RFC1195]/ ?

    I wondered about this too when I was reviewing the document, and indeed RFC 5305 just calls the TE Router ID a 4-octet value. But then RFC 6119 says,

       The TE Router ID TLV contains a stable IPv4 address that is routable,
       regardless of the state of each interface.

       Similarly, for IPv6, it is useful to have a stable IPv6 address
       identifying a TE node.  The IPv6 TE Router ID TLV is defined in
       Section 4.1.

    So even though it was after the fact, I suppose calling the former the “IPv4 Router ID” makes sense and just codifies what is apparently already the practice. The existence of the IPv6 TE Router ID, so named, is “the exception that proves the rule”. 

    $0.02. The authors might have additional comments of course.

    > ### Section 7
    > 
    > While Les was not an author of RFC 5316, he is an author of this I-D, so no
    > more need to acknowledge him ;-)

    I did make this point during my review and the authors chose to clarify that the supplied acknowledgments are a verbatim copy of what was in RFC 5316. So although this is a little unusual, it was a deliberate choice.

    FYI, FWIW,

    —John