Re: [Idr] AD Review of draft-ietf-idr-tunnel-encaps-15

[Alvaro Retana <[e-mail]>]

Hi!

Ok, that’s fine.

Thanks!

Alvaro.

On June 26, 2020 at 10:47:20 AM, John Scudder ([e-mail]) wrote:

> On Feb 21, 2020, at 7:47 AM, Alvaro Retana <[e-mail]>
wrote:
...
> 934 3.7. Prefix-SID Sub-TLV
...
> 947 The Prefix-SID sub-TLV can occur in a TLV identifying any type of
> 948 tunnel. If an Originator SRGB is specified in the sub-TLV, that SRGB
> 949 MUST be interpreted to be the SRGB used by the tunnel's egress
> 950 endpoint. The Label-Index, if present, is the Segment Routing SID
> 951 that the tunnel's egress endpoint uses to represent the prefix
> 952 appearing in the NLRI field of the BGP UPDATE to which the Tunnel
> 953 Encapsulation attribute is attached.
>
> [major] Except for the first sentence, this paragraph says the same
> thing as rfc8669. Please don't re-specify the behavior here (unless
> it changes, of course); instead, point at the source.

The quoted paragraph talks about how the Prefix-SID Sub-TLV is to be
interpreted, in relation to terms defined in RFC 8669. RFC 8669 is — of
course — the authority regarding what those things mean, but tunnel-encaps
has to tell the implementor how to map the fields in the sub-TLV into the
constructs defined in 8669. It may seem obvious that the fields relate to
“the tunnel’s egress endpoint” but it still seem better to say so than to
leave it up to the creativity of the implementor. So, I don’t think
tunnel-encaps is re-specifying at all. We’ve let the paragraph stand as
written.

Thanks,

—John