About 2 ISPs in 1 router or wan router. is it possible?

Unanswered Question
Mar 23rd, 2009

Hi again to all cisco net experts.. i would like to ask your thoughts, opinions or anything that you like to share with me.. here it goes:

Just recently 1 month ago, we had some internet disconnection problems encountered which is came from our service provider. And we expect this to be happen soon or later. Now, my company or the owner is proposing another service provider which is it could be used as an alternative or it can be used as load balancing/fail over or switching to other ISP. I heard this many times from the other sites, forums. My boss can't afford this kind of problem and i asking your thoughts regarding this issue directly to you guys from the CISCO experts.

Also, we have a file server here, its a VINE LINUX.. if in case the proposal will be implemented..

- Is this possible?

2 ISPs-->WAN ROUTER-->1 FILE SERVER (Linux)-->2 LANs (but separate for example, LAN1=ISP1 and LAN2=ISP2)-->Clients

[Note: I would like the file server to be connected in wan router, if possible, then it would be good also]

- are there any conflicts?

- any advantages/disadvantages for this kind of networking setup?

I have this problem too.
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thotsaphon Mon, 03/23/2009 - 11:07

Hi wilson,

What Paolo has provided is a good solution for you. It will help you to do load-sharing outbound between 2 WANs. What I'm concerned about is as follows:

- You may have to configure both DNS servers each ISPs on your internal dns server.

- You may experience using DNS from ISP-A but connect to the internet via ISP-B. That's okay for some reason.

- In case you want to do load-balancing inbound. You won't get what you want. Let's say you have an internal server that can be connected via the internet. What you're going to do is that you may think about how to solve different public ip address among 2 ISPs as round-robin method or something like that!. You may need to have some kind of load balance box in your network and separate WAN routers for this kind of requirement .

Poalo, How are you going? I'm just back to this forum.



johnclever Wed, 03/25/2009 - 23:15

hi guys from cisco experts. i would like to show to you a sample network diagram of an existing network and proposed network with the involved of 2 ISPs and WAN router.

i am attaching an image just below if you wish to see it and to be able to understand what i am supposed to ask and show it to you know visually. on the image content, there is a 2 questions indicated and you are welcome to answer it. this would be a big help to me just in case or before the proposal to be implemented. i am not an expert on networking but i am eagerly and currently studying by myself.. basically or average i did some experience about networking stuffs.

i really appreciate on your important response and maybe you can give some tips and tricks on me.. hehehe thanks


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