Subject: [Lsr] Questions about draft-ietf-lsr-flex-algo-06

From: <[email-masked]>
Date: Sat, 29 Feb 2020 14:41:59 +0800 (CST)

Hi Peter

Please see the difference rules of TE metric in Flex-algo draft and RFC5305.

For  the link without TE metric attribute, in Flex-algo draft it will be excluded from FA plane that configured TE metric type, but in RFC5305 the IGP metric of the link can be as replacement.

Please see if they can be consistent ?

Flex-algo draft:

section 12.  Calculation of Flexible Algorithm Paths

Rule-5:

 5.  If the Flex-Algorithm definition uses other than IGP metric

      (Section 5), and such metric is not advertised for the particular

      link in a topology for which the computation is done, such link

      MUST be pruned from the computation.  A metric of value 0 MUST NOT

      be assumed in such case.

RFC5305:

section 3.7.  Sub-TLV 18: Traffic Engineering Default Metric

This sub-TLV is optional.  This sub-TLV SHOULD appear once at most in

   each extended IS reachability TLV.  If a link is advertised without

   this sub-TLV, traffic engineering SPF calculations MUST use the

   normal default metric of this link, which is advertised in the fixed

   part of the extended IS reachability TLV.