James, Community lists and route maps but the place to start is a sheet of paper and to think about what your goal is. Its quite easy (especially on large networks) to build contradictory logic. Also beware what implications you have for cost and capacity. E.g. A customer could signal send all my traffic via $expensivetransit and you then lose money quick. Communties are also good for blackhole signalling but remember your customers will raise queries when deploying them too! Regards, Neil -----Original Message----- From: James Blessing <james.blessing@entagroup.com> Sent: 19 November 2007 07:17 To: nanog@merit.edu Subject: BGP Communities Hi, Following up on the thread about BGP communities, I was wondering if there is a guide on how to actually implement communities within a network... There are a couple of presentations about why communities are good and about the general design of communities but my googlefu has so far not found a "Here is how to deploy Communities" guide that takes into account the important things like configuration maintenance, how to scale and what mistakes not to make. We are a Cisco house so any Cisco specific documentation would be great but any guide right now would be a start. J -- COO Entanet International T: 0870 770 9580 W: http://www.enta.net/ L: http://tinyurl.com/3bxqez