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New Member

access to multiple ISP's

Here is my problem, I was an internet boundary router and I want it to connect to two different ISP's for redundancy, say through int s0 for ISP1 and for int s1 for ISP2. I know I can using floating static route, so that when one interface goes down, the other keeps on working or comes up, as the case maybe.

But how can I configure load balancing as well, ie use both the links for dividing up the internet traffic as well as if one of them goes down, the other one comes up?

4 REPLIES
New Member

Re: access to multiple ISP's

For your scenario theres one solution, implement BGP routing protocolo, the problem is that you need to be a big carrier. That´s because this option is frecuenly use for carrier interconection. The other option is use two routers using HSRP(cisco use this name), where you have for you clients a one logical gateway, but in reality 2 routers, then when one go down immediately the other, that was in standby, go up. In this way you have completely redundancy. In Cisco search there are many examples if you put HSRP.

New Member

Re: access to multiple ISP's

I have some questions about your case:

Does your router belong to different AS with ISP1&2?

Do ISP1&ISP2 have different AS number?

Who assign IP address for you, ISP1 or ISP2?

I think different answers of those questions will have different solutions.

New Member

Re: access to multiple ISP's

You can try out by putting blind routes like

ip route 0.0.0.0 0.0.0.0 ( remote wan ip address of int s0> and

ip route 0.0.0.0 0.0.0.0 ( remote wan ip address of int s0>

the AD and metric value for both the routes are same so loadbancing starts.

You can verify this by traceroute command.

New Member

Re: access to multiple ISP's

Are you sure configuring two default routes on the same router will work?

anywayz, lets assume both the ISP's are different, so they belong to different AS's...and each of them have given me a different IP address, both of s0 and s1 links....I dont want to configure an dynamic routing protocol, all I want is to load balanace between the two links as well as configure redundancy.

Is it possible to do that through policy routing, say on the ethernet interface. say, for some traffic like FTP, policy route to ISP 1 and for other ytraffic, say telnet and http, policy route to ISP2? But will that allow redundancy as well?..so that if one link goes down, the other link can be used for all traffic?

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