Subject: Route Reflectors and IPv6

From: Mareline Sheldon <[email-masked]>
Date: Tue, 11 Feb 2003 06:05:20 -0800 (PST)

Hello,
The standard says that if the remote router ID is not configured then a router may include its
IP address in sending the originator id. What will happen in case when i have peering using
IPv6? In that case i will not be having an IPv4 address to fill. 

Has any thought gone on this?

Regards,
Mareline S.

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From: "John G. Scudder" <[email-masked]>
Date: Tue, 11 Feb 2003 10:20:16 -0500

At 6:05 AM -0800 2/11/03, Mareline Sheldon wrote:
>Hello,
>The standard says that if the remote router ID is not configured 
>then a router may include its IP address in sending the originator 
>id.

It's not clear what the referent of "the standard" is here.  I'm 
assuming RFC 1966, but RFC 1966 doesn't say anything about using your 
IP address as the originator ID, it says to use your router ID.  With 
our new focus on correct use of terminology, this would more 
accurately be "BGP Identifier."

>What will happen in case when i have peering using

draft-ietf-idr-bgp-identifier-01.txt

>Has any thought gone on this?

I do not Yahoo.

--John

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From: Mareline Sheldon <[email-masked]>
Date: Wed, 12 Feb 2003 05:37:26 -0800 (PST)

okay .. so then it becomes mandatory for everyone to explicitly configure a BGP ID which needs
to be unique in an AS! This is somewhat problematic coz till now we were not necessarily
explicitly configuring BGP IDs for if none was given then it would automatically pick out one
from its interfaces.

This will not be possible in an IPv6 network now coz all the interfaces will be assigned IPv6
addresses.

Mareline S.

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From: Micah Bartell <[email-masked]>
Date: Wed, 12 Feb 2003 10:01:47 -0600

I would think that explicitly configuring BGP IDs is a good best
practice.  I know that having the router automatically use one
of the IPv4 addresses on the router could result in problems
such as when anycast RP is used for multicast.

In the case of IPv6 only, there is no way to guarantee that any
32-bit integer generated based on internal information is
unique in the domain.  I think in the long run, separating the
BGP ID from the actual addressing is beneficial with BGP being
used in a multiprotocol fashion.

/mpb

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From: Jeffrey Haas <[email-masked]>
Date: Wed, 12 Feb 2003 12:02:05 -0500

On Wed, Feb 12, 2003 at 10:01:47AM -0600, Micah Bartell wrote:
> practice.

I haven't had the time nor the data to analyze a live network.
However, I have a large suspicion that on a router with a reasonable
number of external peering sessions that the tie-breaking will get
down to routerid in a significant number of cases.  This means that
choosing a router-id intelligently may seriously affect route selection.

This is a gentle reminder to implementors that having some way to 
extra at what point a route was selected in the tie-breaking process
would be a damned handy thing to have in your CLI.

-- 
Jeff Haas 
NextHop Technologies