I faced a similar situation on a client's network a few weeks ago. The problem was related to extensive FULL route databases being transferred from the ISP peers down to each on the client's routers. On top of that, the client routers had an extensive Access-list (more than 50 entries each).
Obviously, the BGP FULL route updates and the Access-lists where taking a high toll on the router's (3640) CPU and memory resources, causing them to reset the WAN interface. We fixed the problem in a two step process: Step One: Immediate "flapping problem" fix Allow peering between RTRA and RTRB, to exchange only local routes. Step two: Long term effect and stable BGP routing Request that both ISP's send only partial BGP routes (their own routes), not FULL route databases. Fine tune the peering with both ISP's and influence the path selection using route maps accordingly. Trim down the Access-list (left just 5 entries). They had a Firewall-1 installed. So the router was left to do ROUTING and the Firewall to do "Firewalling". Hth, Angel -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED] Sent: Wednesday, December 19, 2001 11:39 AM To: [EMAIL PROTECTED] Subject: BGP Help [7:29650] Greetings all, I was wondering if you guys can help out with this problem. We're connected to both Sprint and UUnet and receiving full routes. All routers are peering with each other. My problem is with both RTRA and RTRB, they're flapping constantly, RTRC and RTRD are very stable. Is there a knowing cause am missing here? any suggestions would be great. Thanks.....................Nabil RTR A- - - - - - - - - - - - - - - - - - - - RTRB | | | | | | | | RTRC RTRD Sprint UUNET Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=29661&t=29650 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
