I am using Time Warner cable internet service. My IP address changes every couple months. However, I need to access some access limited servers which has firewall rules on it.

Is there any way to make my IP address fixed so that no need to change firewall rules whenever my IP address changes?

  • 1
    The word(s) you are looking for is a "static IP address."
    – David
    Nov 17 '10 at 19:04
  • Maybe it's time to mark this as answered? I'm not trying to cause problems. You have several people that have given the exact same advice, so it's likely that it is relatively accurate. Just a thought.
    – Everett
    Nov 20 '10 at 15:39

Dynamic DNS (DDNS) is what you need if you don't want to pay for a static IP, but as Arjan pointed out DDNS only works for inbound traffic. As I see it you have three options:

  1. Pay Time Warner for a static IP address.

  2. Set up a proxy server that will send its IP address (which will be static) instead of your IP address.

  3. Use third party firmware on a suitable modem and force a static IP address. Not sure what your terms and conditions are with Time Warner, but in all likelihood they will not like this and might cancel your service if they find out you are doing it.

  • 1
    That won't help with firewall access however.
    – Cry Havok
    Nov 17 '10 at 18:56
  • @Cry it will if he bases his firewall rules off of the DDNS url instead of an IP address. Nov 17 '10 at 19:28
  • the OP is talking about accessing third-party servers (which apparently filter by client IP address). DDNS only helps for incoming traffic, not for outgoing traffic.
    – Arjan
    Nov 17 '10 at 19:34
  • @Arjan the OP says "so that [there is] no need to change firewall rules whenever my IP address changes" indicating that he does have the ability to change the firewall rules. You are of course right about DDNS only working for inbound traffic. The OP could look into setting up a proxy server, but I have never found a free and (legal) way to set up a WAN proxy. Another possibility would be third party modem firmware (Haxorware majorthreat.net) which would allow the OP to specify a static IP, but Time Warner wouldn't like this at all. Nov 17 '10 at 20:26
  • @Arjan yes we do, I have edited my answer. Nov 17 '10 at 20:41

Only your ISP can give you a fixed IP address. You could look to using a VPN to a device on a fixed IP address (for instance a virtual server you managed yourself), but that's about your only other option.

Alternatively you could talk to the admin of the server and see if they can set it up so that you can use a VPN to access the server.


Security by blocking IP-addresses is primitive.

But like Cry Havok wrote, talk to your ISP. Keep in mind that a fixed IP usually costs more than a dynamic one.


If your firewall allows you to set up rules by URL you might want to try out a service like http://www.dyndns.com

Most routers have options for dyndns and such or you can install a client on your machine to update your IP with the dyndns service

  • 1
    While dyndns is an excellent service, it won't help him in this case. Nov 17 '10 at 17:57
  • @Joel Why wouldn't it? Nov 17 '10 at 18:15
  • 1
    Read the question. He has to log in an outside service that restricts him to a certain IP address. He needs to reach outside, not allow someone to reach back in. He needs a fixed IP, not just a fixed domain name. Nov 17 '10 at 19:35

You can get a Panix account for $100 per year and use their privoxy service (a web proxy run on their server). Since their server never changes IP address it would not matter what your ISP assigns you.

I have no business relationship with Panix except being a long-time satisfied customer.


As I understand it, you would have to switch to Business Class Service through Time Warner Cable. I'm sure there is a fee involved, and likely a change in the cost of your monthly service. This would be the direct answer for how to get your ISP to give you a Static IP address.

DynDNS is a solution if (and only if) the firewall you are talking about does a reverse lookup to find the name of the domain the source IP address is in (your public IP address in this case), instead of the IP address itself. You stated your concern was based entirely on the IP address, not the domain name. I suspect DynDNS will be of little use in this scenario. I suspect this because although your IP address changes from time to time, your domain does not (if you are even part of one) when using DHCP (dynamic IP addressing) through Time Warner Cable.

  • Even if the firewall would do a reverse lookup, I doubt that the DynDNS name would show up then? The owner of the IP address is still the cable company, hence I assume that in the end the data of their DNS servers will be used for the reverse lookup.
    – Arjan
    Nov 17 '10 at 19:37
  • The Domain provided by DynDNS would be the one searched in the reverse lookup. The reverse lookup would show the dynamic IP address that Time Warner Cable provides. This is the point of the service DynDNS provides. As I stated it is unlikely to solve the problem, because you are still using a Dynamic IP address instead of a static one.
    – Everett
    Nov 17 '10 at 19:46
  • A normal lookup would show the IP address, given the domain name. A reverse lookup shows a name, given an IP address. The name found in the reverse lookup won't be the DynDNS name, right? (Hence DynDNS is never a solution for this question?)
    – Arjan
    Nov 17 '10 at 20:35
  • Are we arguing that DynDNS isn't the solution (which we've both stated) or something else? I stated that the Firewall would have to be concerned about the Domain name, and do a reverse lookup. The firewall would have an IP address from the client computer, and now, as being concerned about the Domain name, would want to see what it is. If the domain is registered with DynDNS, they would likely be the ones to provide the name as they are the registrar for it, right? Isn't that the point of DynDNS? Also note I mentioned that it sounds like the IP address is the concern. We agree, yes?
    – Everett
    Nov 19 '10 at 17:13
  • How DynDNS works according to DynDNS: How does Dynamic DNS work? Most residental internet connections use a dynamic IP address, which changes weekly or daily. This prevents visitors from easily finding their networks. The Dynamic DNS and Custom DNS services fix this problem by giving you a human-readable hostname, such as yoursite.dyndns.org or yourdomain.com, which is updated automatically with your IP with a special update client. This allows visitors to reach your home network without needing to know the IP address ahead of time.
    – Everett
    Nov 19 '10 at 17:43

Change internet service and get a static ip

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