Early Review of draft-ietf-rtgwg-bgp-routing-large-dc-05
review-ietf-rtgwg-bgp-routing-large-dc-05-rtgdir-early-hares-2015-07-23-00

Jeff, Chris, Petr, Ariff, and Jon:



This is a second routing directorate review of
draft-ietf-rtgwg-bgp-routing-large-dc-05.  The rtgwg chairs asked me to provide
my insights as a BGP person for many years.





Status:  Publish after correcting a few BGP issues

·



Great leaps forward from the Original document, and an interested document to
read.

·



A few minor technical issues,



Editorial issues: As the second reviewer, I did not focus on the editorial nits
and errors.   The English could still be improved in many sections.  If the
chairs wish me to pull out my scholarly red pen,  I will do so.



Minor technical issues:



1)



P. 5 – ANYCAST and ECMP have been a fine idea for 8-10 years.

2)



P. 10 – Your TRILL comments could use a bit more clarity.



Here’s the facts



2-a) TRILL (Huawei) and “early TRILL”  (Cisco, Brocade) – have been deployed in
the Layers 2 design.  TRILL requires special forwarding (due to header), but
there is a draft to use  TRILL over IP (
  http://datatracker.ietf.org/doc/draft-ietf-trill-over-ip/) .



The TRILL forwarding has had active-active added to its capability which deal
with the broadcast/undefined multicast (BUM traffic).



TRILL deployment make use of the proprietary directory services in order to
reduce the BUM traffic or the IP/MAC look up traffic.   Five new drafts are
heading toward the IESG that allow a standardized directory service (2 provide
over-all designs for service, and 3 provide additions to standard trill).



TRILL shares its OAM with the 802.1ag OAM so that the fault-management and
performance management can utilize the automatic features design by 802.1.



The

draft-ietf-trill-irb-06

 solution may help your L2/L3 Design by providing a clear TRILL/Layer-3 gateway.



3)



Section 5.1 page 12

a.



“BGP deployment within an Autonomous system typically assumes the presence of
an IGP for next-hop resolution”



Here – BGP can run without an IGP by using the features of ARP/RARP and ND.
  This feature has been true of BGP since 1987.



4)



P.AGE 13 “This meets REQ 3 and REQ 4.  It is worth mentioning”

I suspect you mean “This use of E-BGP meets REQ3 and REQ4.”



However, I could not tell and that’s important for the technology.





5)



You should cross reference AS-Migration and other drafts that have
“Remove-PRIVATE-AS” before sending out.



6)



Multipath-relax should be described in specific detail in a different document
if you think is very useful (p. 20)



7)



Section 7.1 IDR drafts:

draft-ietf-idr-rs-bfd-01

, and

draft-jdurand-auto-bfd-00

 are proposing BFD/BGP interactions for Route-servers.  You should review this
 documents and link to these documents in your draft.



8)



Section 7.2 – You mention Add Paths in many section, but a lot of your problems
might be solved with Add-Paths and a guideline on how to reduce the FIB.   One
way to also aid Add-Paths is to allow for custom cost community to be added at
certain points.  You do not consider this option.





Sue Hares