BGP TTL

[Aditya]

On Wed, Mar 20, 2002 at 02:38:14PM -0500, Andrew Partan wrote:
> A brief discussion over lunch brought up the idea of adding a BGP
> attribute - a TTL - to limit how far (by AS count) a route will
> propogate.
> 
> I.e.: set TTL to 1 and your route only goes to your neighbors.

ie. community no-export

> Set TTL to 2 and it only goes to your neighbors and their neighbors.
> 
> It might also help to limit the BGP ASPATH count-to-infinity problem
> when you withdraw a route (as you will only count to the TTL).
> 
> This may not be useful in all cases but I suspect that it would be
> useful in enough cases that I think we should add this tool.

so could you give an example where you wouldn't use community no-export nor a
pre-agreed upon community between multiple AS (neighbors and their neighbors)
that this would be useful? 

NB. not questioning the idea, but just trying to envision where it might be
useful.

Adi