Subject: BGP Identifier in draft-ietf-idr-bgp4-18.txt

From: Manav Bhatia <[email-masked]>
Date: Fri, 14 Feb 2003 09:31:03 +0530

Hi,
draft-ietf-idr-bgp4-18.txt explains the BGP Identifier as :

"  A 4-octet unsigned integer indicating the BGP Identifier of the
   sender of BGP messages. A given BGP speaker sets the value of its
   BGP Identifier to an IP address assigned to that BGP speaker. The
   value of the BGP Identifier is determined on startup and is the
   same for every local interface and every BGP peer."

I think that the current definition is a little ambiguous and can be
re-worded.

BGP Identifier is generally taken as the Loopback address and not
necessarily the "IP address assigned to that BGP speaker". I could have two
interfaces 1.1.1.1/24 and 1.1.2.1/24 and i could have BGP peerings over
these two interfaces. For one peer the IP address assigned to this BGP
speaker is 1.1.1.1 while for the other one it is 1.1.2.1.

So by the current definition the BGP ID wouldn't be the same for every
local interface and every BGP peer.

We need to stress more on the fact that it needs to be unique and same for
all the peers on every local interface.

Regards,
Manav

----
Senior Software Engineer
Samsung India Software Operations
Bangalore - 560 001
+91-80-5550555/6 (1120)

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From: Mathew Richardson <[email-masked]>
Date: Fri, 14 Feb 2003 11:12:26 -0500

> Manav Bhatia <[email-masked]> [Fri, Feb 14, 2003 at 09:31:03AM +0530]:
>Hi,
>necessarily the "IP address assigned to that BGP speaker".

It says "_an_ IP address assigned to that BGP speaker", not _the_.

>                                                            I could have two

No.  If those were the only two IP addresses assigned to the BGP speaker
then the BGP Identifier would be one of those.  It would be determined
on startup, and be the same for every local interface and every BGP peer.

>all the peers on every local interface.

<snip>

From the text that you quoted:  "The value of the BGP Identifier is 
determined on startup and is the same for every local interface and every
BGP peer."

I don't think it's possible to get much clearer than that.

mrr