Dual Wan on a 1841

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Dec 23rd, 2008
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I have a 1841 that I am looking to setup Dual WAN Dual NAT.

I know that you are not supposed to have the DMZ on a VLAN but did not have a choice at this point.

Here is my question I have one T1 and one DSL line that I need to be able to use. The DSL is for most of the traffic and the T1 is just for the servers. I have use a route map on the old router to send the server traffic out a different default gateway. I am using a lot of nat forwarding to get the outside traffic in if I change the default gateway to the DSL the router does not send the data back.

I have also made nat forwarding for the server that are very important on the DSL line so I could have a backup route.

What should I do?

Should I try a route map? but that would kill the backup DSL line traffic?

I would also like it if the DSL was down the T1 would get all traffic.

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Giuseppe Larosa Fri, 12/26/2008 - 02:41
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Hello John,

if the two links are from different service providers you need to use two different public address pools one from ISP1 and one from ISP2 and you need to use isp1's block when using link to ISP1 and ISP2's block when using link to ISP2.

I see only one address block in your configuration.

use the following document as a reference


Hope to help



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