4. Deployment Consideration

This section preserves the RFC text for IGP Flex-Algorithm reverse affinity constraints, including FAERAG, FAD, IS-IS and OSPF Sub-TLVs, reverse Administrative Groups, IANA registrations, and path pruning rules.

Original RFC Text

4.  Deployment Consideration

   Threshold-based setting of the link Extended Administrative Groups
   must be done with care to avoid excessive flooding and constant Flex-
   Algorithm path recalculation.

   One possible approach is to use two different thresholds when setting
   and unsetting the Extended Administrative Group on the link.  For
   example, when setting the Extended Administrative Group on the link
   based on the percentage of certain incoming errors, higher threshold
   is used for setting and lower threshold is used for unsetting the
   Extended Administrative Group on the link.

   Many implementations provide a throttling mechanism that limits the
   rate at which the Link State PDU (LSP) in case of IS-IS, or Link
   State Advertisement (LSA) in case of OSPFv2 and OSPFv3, is updated at
   the originator.  Such mechanism is typically not specific to any
   particular link attribute, but rather considers any change in the LSP
   or LSA.  Application of such throttling mechanism can also be used to
   avoid frequent changes in the setting of the Extended Administrative
   Group on a link to affect the stability of the receivers.