Re: RTGWG LC for draft-ietf-rtgwg-bgp-routing-large-dc

Anoop Ghanwani <> Thu, 06 August 2015 02:05 UTC

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Subject: Re: RTGWG LC for draft-ietf-rtgwg-bgp-routing-large-dc
From: Anoop Ghanwani <>
To: Jeff Tantsura <>
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Support.  I have mostly minor comments included below.



Section 2.3
I had trouble understanding this statement:

   Operating large-scale infrastructure could be expensive, provided
   that a larger amount of elements will statistically fail more often.

Is it just trying to say that with a larger number of elements, likelihood
of seeing failures goes up?  Or is it saying something else?

Section 3.2.4

   If a data center network size is small, it is possible to reduce the
   number of switches in Tier-1 or Tier-2 of Clos topology by a power of

Should this say factor of 2?

Section 4.1

   The major downside of this
   approach is the proprietary nature of such extensions.

The bigger issue is probably limited scalability because of the need for
synchronization between switches at a given tier level where the protocol
is implemented.  Also wastage of ports to implement the inter-chassis
link.  I say that because a standard for this now exists -- 802.1AX DRNI,
so technically, the proprietary nature is no longer a limiting factor.

Section 4.1, para 2

currently the maturity of the protocol

Did you mean lack of maturity?

Section 4.3

   Application providers and network operators continue

   to also develop new solutions to meet some of the requirements that
   previously have driven large Layer 2 domains.

Would be good to add a reference.

Section 5.2.1

 A unique ASN is allocated per each group of Tier-2 devices.

By group, do you mean all of the switches in a cluster (cluster being a
term previously defined)?  Or is group something else?

Typos and minor editorial

Section 2.4, line 6
situation -> situations (or a situation)

Section 4.1, line 11
larger topologies many of the fundamentals ->
larger topologies, many of the fundamentals

Section 4.2, last bullet
Layer-2 -> Layer 2
Layer-3 -> Layer 3
(Only instance where hyphens are used :))

Section 5.1, bullet 6

It is worth mentioning that all widely deployed
      link-state IGPs also feature periodic refreshes of routing
      information, while BGP does not expire routing state, even if this
      rarely causes significant impact to modern router control planes.

would read better as

It is worth mentioning that all widely deployed
      link-state IGPs also feature periodic refreshes of routing
      information even if this
      rarely causes significant impact to modern router control planes,

      while BGP does not expire routing state.


Section 5.1, last bullet

Section 5.2.3
The section Section 8.2 -> Section 8.2

Section 5.2.5

Section 5.2.5, 2nd bullet

device with the other devices in the Clos

change to

device compared with the other devices in the Clos


Section 6.1, 3rd para, 2nd line
step (e) Section -> step (e) in Section

Section 6.4, line 1
used to ECMP -> used for ECMP

Section 6.4, line 2
minimizing -> minimize

Section 7.1, 3rd para, 1st line
Ethernet technologies -> Ethernet links (or platforms)

Section 7.1, 2nd line from bottom
it's -> its

Section 7.4, 1st para after bullets, line 2 from bottom
only store -> only stores

Section 7.5, line 4 from bottom
server IP address subnet -> server IP address subnets

Section 8.1, 1st para, last line

Section 8.2, 2nd para, line 2 from bottom
Tiers -> tiers

Section 8.2.2, line 9
there is no failures -> there are no failures

On Sun, Aug 2, 2015 at 8:31 PM, Jeff Tantsura <>

> This email is to start 2 weeks RTGWG LC for
> draft-ietf-rtgwg-bgp-routing-large-dc-05
> Authors have addressed all the comments.
> Please indicate support or no-support as well as your comments by August
> 18, 2015.
> If you are listed as a document author or contributor please respond to
> this email stating of whether or not you are aware of any relevant IPR.
> The response needs to be sent to the RTGWG mailing list. The document will
> not advance to the next stage until a response has been received from each
> author and each individual that has contributed to the document.
> Thanks,
> Jeff & Chris
> _______________________________________________
> rtgwg mailing list