Thanks Bill... "finally, 'down' can mean a lot of things and your customer needs to figure out if that means 'interface loss', 'loss across cogent' (frequent occurrence), 'latency spike', etc. in IOS, using IP SLA and a track object is probably the best way to implement those checks"
This is a very good point - there's a good reason they need backup when using a Cogent feed ;) Sorry, couldn't resist saying that... their viewpoint will be "loss across cogent" I'm sure... I believe they will want a full feed and just look after it all - or we can offer them a managed customer prem router solution and take care of it for them.... Take care, Paul -----Original Message----- From: bill fumerola [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 23, 2008 12:26 PM To: James Slepicka Cc: Paul Stewart; 'cisco-nsp' Subject: Re: [c-nsp] Conditional BGP On Tue, Sep 23, 2008 at 09:23:16AM -0500, James Slepicka wrote: > >>they both wish to use us as a backup provider and wish to ONLY use > our network if their primary provider (Cogent) is down. > > I'm currently doing this with Cogent and another provider. I get > default routes from both and simply prepend my AS a few times on the > backup connection. In your situation this would mean that all of the > config is on the customer side. e.g.: > > router bgp xxxx > ... > neighbor backup route-map prepend_outbound out > neighbor x.x.x.x peer-group backup > ... > > route-map prepend_outbound permit 10 > set as-path prepend xxxx xxxx xxxx avoid manual peer-groups.. templates using 'inherit peer-(session|policy)' are more flexible and easier to change later. if your neighbors have the same outbound policy, they'll get stuffed into the same update group w/o the peer-group. and to answer the OP question: this is a question of local policy for the customer. give them lots of options. let them use weight (and/or localpref, if they have multiple routers in the AS) to determine egress. give them communities if that will help their route selection decision making. i wouldn't go much further than the previous suggestions of 'full routes', 'customer routes', 'default origination' unless $customer is paying you to rig something up or you're feeling particularly nice. finally, 'down' can mean a lot of things and your customer needs to figure out if that means 'interface loss', 'loss across cogent' (frequent occurrence), 'latency spike', etc. in IOS, using IP SLA and a track object is probably the best way to implement those checks. -- bill _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
