General discussion

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  • #2188816

    Cisco 1700 series general config


    by natecasp ·

    We have a 1720 series router with a T1 CSU/DSU WIC. The router is working now but is using NAT between my firewall and the T1 interface. I have 5 usable IP addresses and would like to configure the router without NAT and assign public IPs to both the Ethernet IF and firewall ports. I think I need to use the just assign one public IP address to the E0 port and the next one to my firewall. Then remove the network from the E0 interface but how do I configure routing and remove the address translation?

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    • #3045514

      Reply To: Cisco 1700 series general config

      by evkuo ·

      In reply to Cisco 1700 series general config

      I’d check with your ISP, but usually you can do it one of two ways:

      1. Setting your S0 interface to unnumbered and then giving the public IP to E0 (see Then, since they’re on the same subnet, you don’t have to do much routing on the interfaces.

      2. On PTP lines, set the S0 interface on the routers on both sides to a highly restricted subnet (let’s say so one side will have and the other Then you’ll need to set the routes accordingly.

      Either way, I’d have the firewall do the NAT’ing and remove all ip nat and nat pool statements on the 1700. It might be cleaner to just re-do the 1700, but I’d backup the config via TFTP (or just cut and paste it to a text file) before I did that.

      • #2593949

        i need help with cisco1720 conf

        by rcs29us ·

        In reply to Reply To: Cisco 1700 series general config

        the ip ths service provider gave me are:
        for example:

        how do i assing that to the router to be able to connect to the internet????


        • #2585555

          Use ip adress comand

          by kpese2000 ·

          In reply to i need help with cisco1720 conf

          Use the ip address command on the either the serial interface or ethernet int to assign ip addresses e,j:
          config t
          int s0 0r e0
          ip address
          no shut

          You still need to come out with more details as to what you are asking.

        • #2612900

          I dont have the answer just another ?

          by chrisnett ·

          In reply to Use ip adress comand

          I have a 1750 with IOS c1700-k2o3sy-mz.121-22c.bin with a ADSL WIC

          I have 5 static ips assigned by my ISP sbc.
          They provided me with a natopia 3346n ADSL gateway. I’m confused on two things.

          1. The gateway has one RJ 11 that is comming through the wall jack, and it has 4 ports for cat5. How do I plug it into the 1750?

          2. How do I config the router to communicate with the gateway?

          I’ve only completed CCNA 1-3 at the acadamey.
          please help.

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