Cisco 1811 Router Configuration - Two Internet Connections - Redundancy

Posted on 2011-05-12
Last Modified: 2012-05-11
Anyone have good examples of configuring two Internet connections in a Cisco router?
Current Configuration:
-1 Cable Internet Connection w/static
-Client to Site vpn's setup on this static
-Our Exchange Server Domain name is using this static for RDNS etc

Wanted Configuration
-2 Internet Connections w/ 2 statics
-Exchange to stay on cable Internet connection
-Cable Internet connection for fall over/ secondary
-New second DSL connection as Primary web traffic connection

I have configured both cable and dsl connections independently in Cisco routers before but I have never had two connections in 1 router.

Also, if anyone can recommend best practices for this kind of setup please feel free. ie. Exchange on separate connection etc.
Question by:considerscs
    LVL 1

    Assisted Solution

    All you have to do is configure the interfaces and then use NAT to get to the proper hosts for the services.

    for example
    int fa0/1
    ip address

    int fa0/2
    ip address

    ip route
    ip rotue

    ip nat inside source list 105 interface fa0/1 overload
    ip nat inside source list 106 interface fa0/2 overload

    then make your access lists to control what traffic goes out what provider.

    LVL 16

    Accepted Solution


    1) your router should have 2 wan ports
    2) configure lease line on wan 1 (serial 0)

    for example
    int serial/1
    ip address X.Y.Z.A or ( as per IP scheme)

    3) configure ADSL line on wan 2 (PPEO-Dailer 1-2)
    as you mention you know how to configure

    if your require NAT, you can take help from

    4) configure NAT for exchange on wan 1
    5) configure OWA for exchange on wan 1
    6)create static router topermit traffic on wan2

    for static routes please see this

    7) Site to site VPN

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