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Two inputs into one router?

We need to set up some sort of backup internet service on case our main line goes down. We can get a basic DSL line for cheap. So I was wondering if its possible to run the DSL connection into a second ENET WIC on our 1721? Ideally we would like things to switch over seamlessly, but I don't know if its possible through this router?

Thanks Brian

Reply to
Brian
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Hi Brian,

You can run that DSL connection into the ENET WIC, but if you have any static routes configured they will not be operational when your primary goes down, unless both internet connections are from the same service provider.... and I do not suggest you get two connectins from the same service provider if you are running mission critical stuff.

Thanks

Adam

Reply to
adamclark

Brian,

You can put a static default to your main line and a floating static to your DSL connection and outbound initiated traffic would be taken care of. My concern would be inbound traffic (ie www services, etc). Those things have a static IP address and are reached via a DNS resolution. The problem is that when your main line fails, you would want the DNS resolution for

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to resolve to an IP on your DSL line. I have accomplished this with Cisco CSS' (which are expensive), but am not aware of any cheap, simple solution to this issue. You can also solve this issue with BGP by advertising your subnet to two or more providers, but it doesn't sound like that is an option for you. (1721, DSL)

Regards, Steve

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www.networking-forum.com

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" wrote

Thanks for the input. Actually as far as incoming goes, our main concern would be email. I think that can be made to work by setting a secondary MX record that points to the DSL (we're getting a fixed IP). Run that into the router, then to the email gateway.

Like you said, outbound traffic should be taken care of. I am assuming the router can be programmed in some way to use the DSL as a secondary source for anything outgoing.

Thanks Brian

Reply to
Brian

DUH! I forgot about BGP.... And yeah you could also point your secondary MX record to second "backup" connection. Just make sure that you have RDNS configured correctly for both connections, which means you may have to contact the respective ISPs so that they have you in their DNS zone transfer list and they are in yours. If you don't know if your RDNS is working, AOL is a great place to try.

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is a great tool that I use when configuring redunant ISP connections to mail servers.

Reply to
adamclark

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