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cisco 2951 for BGP at AS edge

Level 1
Level 1


our customer has a server farm in a data center.

At the moment the farm has connectivity with only one ISP but sometimes it has service discontinuity.

Customer wants to become AS and having two ISP connectivity for backup purposes.

He needs to evaluete two  cisco routers to use at AS edge with BGP.

At the moment he says that the throughputh with the server farm is max 15Mbps and in the future he thinks that it will not increase.

We think about cisco2951 routers with 2GB ram.

Is cisco 2951 adeguate for this task ?

best regards


3 Replies 3

John Blakley
VIP Alumni
VIP Alumni

Those should be fine for edge routers. You wouldn't want to bring in the whole internet routing table from the ISP with that amount of memory though, but a default route inbound from the ISP and advertising the networks that the customer owns should be fine.

HTH, John *** Please rate all useful posts ***


excuse me for the questions, but I'm not so expert on bgp

2GB ram isn't enough for full bgp table ?

Can we tell the isp to send us only default route or we must filter routing info to select only the default route ?

And about possible security issues like Internet attacks to che router the cisco2951 colud be enough robust ?



According to this on Cisco's site, you only need about 512Mb...I would've thought it would be a lot more. You can have the ISP send you just a default route also though. Depending on the type of attack, you may need to get the ISP involved to block traffic. If you have 300Mb of traffic coming in from an attack and you only have a 20Mb internet connection, then you can see that it would easily overwhelm you. The router could probably still handle it, but your internet connection would be useless. Control plane policing is good for anything directed at your router like DoS attacks, etc.

How much memory should I have in my router to receive the complete BGP routing table from my ISP?

A. The amount of memory required to  store BGP routes depends on many factors, such as the router, the number  of alternate paths available, route dampening, community, the number of  maximum paths configured, BGP attributes, and VPN configurations. ...Achieve Optimal Routing and Reduce BGP Memory Consumption for more detailed information.

HTH, John *** Please rate all useful posts ***
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