Cisco 1841 ISP failover using HWIC-1ADSL and WIC-1SHDSL-V3

Posted on 2008-11-18
Last Modified: 2012-05-05
currently I have an SDSL and an ADSL on 2 netgear routers from two different providers.  We use the ADSL as a backup when the SDSL goes down.  The problem is that we have to manually move the connection and also change all the IP's and firewal rules when this happens and then put it all back when the SDSL comes back online.

I'm thinking of getting a Cico 1841 with WIC-1SHDSL-V3 & HWIC-1ADSL modules to manage the failover.

the SDSL provider has advised that they can also provide an ADSL connection coming from a different gateway which means that the IP's will always stay the same as they are assigned on authentication whether using SDSL or ADSL.

my question is, if i stick with having two different providers rather than go with the same provider can the 1841 handle the ip changes?  there is a sonicwall firewall after the router that handles all the rules and VPN's.

Question by:anas_elkhani
    LVL 43

    Expert Comment

    The 1841 can handle two ISP's on the same router.  The key is setting up NAT correctly.

    Author Comment

    i'm not sure that will work, there is a sonicwall firewal after the 1841 which controls vpn, access rules etc...

    the mx records of the domaain point to a mail filtering company who then redirect to an ip addres which is NAT'ed to an internal mail server via the firewall.  

    if failover takes place to another ISP all the public ip's will change and no services would be working.  other than local internet access probably?

    am i being really stupid or is this a valid point?
    LVL 43

    Accepted Solution

    Oh, sorry, I overlooked that information.  You are absolutely correct.  I read once about a feature on the Sonicwall with the enhanced license regarding WAN failover which might be an option with the Netgear routers connected to each Sonicwall interface.


    Author Closing Comment

    Looked and found something

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