Announcement

Collapse
No announcement yet.

Cisco Static IP Requires DHCP

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Cisco Static IP Requires DHCP

    I have an ISP that is new to my city that I requested a static ip address with. They gave me the ip, but said to set my server's external nic to dynamic and it will pull the ip address automatically. I told them that I need to have the server's nic set to static, because I have services that run on that address. They told me it was not possible to set the nic static because it must request an address to be stored in the arp table.

    Does anyone know if this is accurate and possible on any Cisco?

  • #2
    Re: Cisco Static IP Requires DHCP

    Not precisely sure with Cisco but this is standard behaviour from many ISPs
    Your IP address is static in the sense that you are dynamically assigned the same IP each time your router connects, so you leave the router as "get address from DHCP".

    Personally, unless you find your IP (which should be visible in the router) changes, I would not worry

    What model of router is it?
    Tom Jones
    MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
    PhD, MSc, FIAP, MIITT
    IT Trainer / Consultant
    Ossian Ltd
    Scotland

    ** Remember to give credit where credit is due and leave reputation points where appropriate **

    Comment


    • #3
      Re: Cisco Static IP Requires DHCP

      I'm not sure of the router number. I have a friend that help them set it up, back in 2003, and he knows they were using Cisco, but he didn't remember the model.

      I understand what they're doing, but how would I be able to set the server's services to listen on a specific ip, if I don't have a static address.

      The only way I can think is to put an external router, and give the external nic on the server a private address.

      What is the purpose of this Static through DHCP setup?

      Comment


      • #4
        Re: Cisco Static IP Requires DHCP

        I think you may be confusing two different IPs
        You router will have a public IP, assigned by the ISP, which you would use e.g. to receive email on.
        It will also have an internal IP, configured on the router, used by your LAN -- for example 192.168.0.1. This will be the external gateway on your servers and will be the IP the server "listens" on
        Tom Jones
        MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
        PhD, MSc, FIAP, MIITT
        IT Trainer / Consultant
        Ossian Ltd
        Scotland

        ** Remember to give credit where credit is due and leave reputation points where appropriate **

        Comment


        • #5
          Re: Cisco Static IP Requires DHCP

          Eh?

          It's a windows small business server, using RRAS, so the server, itself is the router. Normally, both nics are given static ip addresses, one public, the other private (192.168.1.x)

          We have a static, public ip, because our services listen on it, rather than every interface. That way, if we want to run something internally, say, a company web page, we can, and not run the risk of someone from an external source getting access to it. Otherwise, the two websites would see each other listening on the same port, and enter a stopped state.

          What I was saying is, the only way I see resolving this is to put a router between the ISP and the server, then just forward all the ports to the server. That way, the server can have a static ip address, and the router can have a dynamic.

          Comment


          • #6
            Re: Cisco Static IP Requires DHCP

            How does the server connect to the internet?
            Tom Jones
            MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
            PhD, MSc, FIAP, MIITT
            IT Trainer / Consultant
            Ossian Ltd
            Scotland

            ** Remember to give credit where credit is due and leave reputation points where appropriate **

            Comment


            • #7
              Re: Cisco Static IP Requires DHCP

              Directly to the ISP's hardware... through a modem, right now. Soon it will be through fiber.

              Comment


              • #8
                Re: Cisco Static IP Requires DHCP

                OK, beginning to make sense -- I thought you had a cisco router that you controlled
                If you know the IP / subnet mask etc. they have given you, why not set it on the server and see how you get on?
                Tom Jones
                MCT, MCSE (2000:Security & 2003), MCSA:Security & Messaging, MCDBA, MCDST, MCITP(EA, EMA, SA, EDA, ES, CS), MCTS, MCP, Sec+
                PhD, MSc, FIAP, MIITT
                IT Trainer / Consultant
                Ossian Ltd
                Scotland

                ** Remember to give credit where credit is due and leave reputation points where appropriate **

                Comment


                • #9
                  Re: Cisco Static IP Requires DHCP

                  The information they gave me was wayyyyy out of whack. The default gateway was on another subnet from the ip, and the subnet mask only included 2 ip addresses in it.

                  No, no... lol. The ISP has the Cisco.

                  Comment

                  Working...
                  X