Hi. To maintain uninterrupted services even if one of your ISP's Fail, you need to run BGP. I created a "basics of BGP" document on [EMAIL PROTECTED], and I'm posting it here. I am a consultant looking for work, if you decide to implement BGP, I would like to help.
---Begin crosspost--- 1. Talk to your ISP's and see if they will let you peer with them. This isn't a question that the average helpdesk person is going to be able to answer, so you may have to work your way up the food chain. If the answer is no, then select a new ISP. 2. Apply for a Autonomous Sytem Number from Arin. This Requires ARIN membership ($500 one-time, $30 annual). If you are not in the continental US, substitute RIPE or APNIC for ARIN. 3. Acquire a minimum of a /24 (256 Ip's) from at least one of your ISP's. 4. Acquire the following information from each of your ISP's. 4a. Ip Address of the Peer 4b. AS# of the peer 4c. Authentiaction (if any) 5. Provide each of your ISP's with the following info.\ 5a. Your Peer IP address 5b. Your AS# 5c. Authentication (if any, not reccomended) 5d. The Subnets you will be advertising (Some ISP's filter the incoming advertisements. Why? Lookup "Blackhole-ing".) 6. Configure BGP on your router. (Imho, preferably cisco.) 6a. Assuming you want to do load balancing, (as best as possible) 6a1. If you have less than 32 mb of Ram, then accept only each providers default route. 6a2. If you have less than 64 mb of Ram, then accept routes from each provider with a as-path of 1 hop or less and each providers default route. 6a3. If you have more than 64mb of Ram, Accept Full routes from each provider and let the router select the shortest AS-path. Monitor your memory usage and maintain at least 12 mb free at any given time. 6b. If you have a primary and a secondary link, and want to prefer one over the other, or want more control over traffic entering and exiting, then use one of the following stratigies. 6b1. As-Prepend to cause the internet to prefer one link or the other 6b2. Set the (Cisco Specific) weight on the preferred link 6b3. Filter to accept summary routes only from one provider 6b3. Use BGP's metrics to reccomend preferences to your ISP's It Seems like a lot, but really it's not that bad. If anyone needs help with this, E-mail me off list. The ISP I work for is expiring and I will be glad to help you out. (As an advisor (free advice), or as a contractor(Price varies from negotiable to negligible.)) Thanks, Ejay Hire [EMAIL PROTECTED] 434-591-4564 ... Have router will travel! ---End Crosspost-- -Ejay Hire [EMAIL PROTECTED] 434-591-4564 -----Original Message----- From: Yassel Omar Izquierdo Souchay [mailto:[EMAIL PROTECTED]] Sent: Monday, February 25, 2002 10:11 AM To: [EMAIL PROTECTED] Subject: TWO ISP AND ONE FAILURE [7:36371] Hello i have a frecuent porblem with one of my isp, i have two cisco routers and each one to different isp. Frequentily i have to change the gateway of one of my servers, because one isp is failure. I want to know if with one of BGP, OSPF, RIP, NAT or other protocol i could do the change automatically to the other active isp. It happening me right now. And when i have to do that i have to reset one of my servers.. :S. Is a costs operatrion its a mail server. So if somebody knows how to resolve between routers with different isp each one, how to route accross the other good gateway. Thnx in advance Yassl Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=36387&t=36371 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
