Nathan, thanks for this idea. Your idea could work. I just need to find out if they will accept my 2x /25 routes if I split the /24.
As for the prepend, how could I deal with peers that might be closer to Cogent than ATT and not load-balance that traffic based on peer's peering location? The usage of Cogent is primarily for point to point VPN backup from other offices that would be on Cogent's network. Ideally I would like to keep that link free of internet traffic unless the primary (ATT) link fails and also not have asymmetric traffic where traffic comes in on the Cogent circuit and leaves on ATT's circuit because of the default route match. I'm not sure if that's possible, but that would be my ideal solution. Thank you, Tom -----Original Message----- From: Nathan [mailto:[EMAIL PROTECTED] Sent: Sunday, October 26, 2008 10:08 AM To: Kacprzynski, Tomasz Cc: [email protected] Subject: Re: [c-nsp] BGP Multihomed Selective/Conditional Advertisement 2008/10/24 <[EMAIL PROTECTED]>: > > I have been trying to figure out how to do this and maybe someone will be able to help me out. > > I have two ISP connections ISP ATT and ISP Cogent. > > (ISP Cogent) (ISP ATT) > | | > RO ------------------- R1 > > > ATT would be used for primarily internet and access to our webservers. > > Cogent would be primarily used to access Cognet's network that use VPN for incoming connections only. I do not want to have other networks besides Cogent's network using this path to access our webserver. > > I would like to have each other act as a backup for one another. For instance if ATT fails I want everyone on the internet use Cogent to access me. If Cogent fails I want everyone on the internet and the VPN connections on Cogent's network to use ATT. > > So basically what I was thinking to setup is to accept a default router from ATT and Cogent. Lower the local preference of Cogent and that way I would accomplish using ATT as primary internet access. I would: -- forget about conditionals -- advertise three routes to Cogent. My whole network, with a lot of prepends, and the two halves of my network, without prepends but with a community saying "don't export". -- receive from Cogent their networks (the VPN things you want) and default. If necessary receive full routes and filter out non-default non-Cogent routes. Set local preference lower than default on default route from Cogent, and local-preference higher than default on Cogent routes. -- advertise whole network to ATT, without prepends. -- receive default route from ATT, with default local-preference. If I've correctly understood what you want then that should do it. -- HTH, Nathan _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
