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fearless.rabbit
Beginner

BGP Multi-homing; Router and config suggestion

Hello everyone,

I am planning an upgrade of a corporate edge network, and I need advice with choosing a router model, and perhaps a little help with configuration of BGP-multihoming.

Attached is a network diagram. You'll notice both routers are simultaneously connected to both ISPs, which is not something I see in Cisco's multi-homing document, where one ISP connects to one router only:

http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13768-hsrp-bgp.html

The routers will be HSRP load-balancing, keeping BGP sessions alive, allow me to manipulate incoming/outgoing traffic preference (download/upload over this ISP, not that one), and monitor and report link health. All links are UTP/Ethernet.

Any advice would me much appreciated!

Thanks,

Milos

8 REPLIES 8

HI,

You can use below concentp

From Router - Use higher weight towards ISP A , so that ISP B on the same router become backup

& Do the same in other router with flip-flop

Use AS-Path prepend for incoming

Br/Subhojit

Thank you, I will surely write that down, and give it a try when I choose, order and receive the routers.

fearless.rabbit
Beginner

Also, what would I need to monitor bandwidth of internet links? I know IP-SLA monitors via ICMP, but I'd prefer an actual

bandwidth monitoring.

Milos,

There isn't an IP SLA option that will automatically switch over to a different link if the bandwidth reaches a predefined threshold. Now, there is a way to do this, and it is called PfR or Performance Routing which used to be called OER or Optimized Edge Routing.

Now you can setup snmp on the router(s), and get an NMS application that can show you link utilization in real time etc, and or NetFlow.

Thanks for replying John. I did some reading, and it all summs up to NetFlow and SNMP basically. The thing is, these methods only show utilization of the interfaces. What I need is to monitor maximum bandwidht of the link (versus used), and to see am I getting what I'm paying an ISP for. If I'm paying, say for 40Mbps, I'd like to monitor if that's what I'm really getting.

Milos,

I understand, makes perfect sense to me

If you're paying for 40Mbps, you're not really going to get the full 40Mbps, most likely around 35 to 39Mbps depending on what connection type you are using, due to protocol overhead, etc.

And usually the ISP is just guaranteeing you that to their PE router. So the CE to PE speed should be around 38 to 39Mbps most likely.

So is there actually a way you can track the performance of their service, and not relly on their dubious ethics?

You can use NetFlow and monitor bandwidth utilization, and possibly do random speed tests if you want, but this all depends on how you view speed tests.

If you go to www.speedtest.net, that measures the speed going from your PC(where you run it) to whatever web server or device they go to, on the Internet, technically outside of your providers AS, so there are a multitude of other areas that could affect this report.

I've known people who are owners of ISPs before, that will QoS speedtests so you get really good results, even though you won't get that speed. Which is a really unprofessional move, but they're are people like that in this industry and or any industry really..