Dynamic IP Address From Wirelss Router

My ISP provides dynamic IP addresses, which I would like to take advantage of.

However, we use a wireless router in our home and from what our ISP told us, if we use a wireless router we can only have one IP adress through a wireless router unless we want to use only one computer at a time and hard wire the ISP modem to out computer.

Is this true?

Thank you.

 

Having a dynamic IP address from your ISP is the normal state of affairs for the majority of home users. There is no way to take "advantage" of this.
What a router, wired and/or wireless, allows you to do is use multiple computers on the one IP address that the ISP assigns you.

Think of it this way.
An ISP has a block of 1,000 IP addresses to use for it's 2,000 customers. Customer #5 boots up and gets an IP address and uses it for 1 hour to surf and then shut downs. Customer #10 boots up 2 hours later and can be assigned the same IP address because #5 is not using it anymore. That way the ISP doesn't have to have an IP address for the absolute number of it's customers. The ISP knows that not all 2,000 customers will be online at the same time so it can share the IP address "dynamically".
You can request a "static" IP address from the ISP but they cost more since that IP address is removed from the pool of dynamic addresses to be used for the other customers. It can't be used by the ISP to share with another customer even if you are not using it.

A home router allows multiple computers to use the ISP assigned address, (which is the public side of the router), at the same time by assigning IP addresses to the individual home computers, (which is the private side of the router). Most normal home routers allow 4 wired connections and multiple wireless connections. The home router accomplishes this by using NAT, Network Address Translation, which changes the private IP address to the public address. Someone looking at the public side of the router only sees 1 IP address while there may be 5 computers using it privately.

If you have programs that need specific IP addresses to work, there are usually static address functions, port forwarding and port triggering options in the home router to accommodate this.

 

Hello, I'm back revisiting this issue.

The answer that lbmest gave was very thorough and comprehensive, but I think it was a bit too sophisticated for me.

My ISP modem provides dynamic, changing IP addresses.

I am not interested in a static IP address, but that's all I get with my wireless router.

Is there a wireless N router available for purchase that will let me have more than one IP address using it wireless? Perhaps one that would change when my ISP modem changes (turning it on and off is all it takes to change the IP address).

eta: there is only one computer in this household.

 

I think you are missing that there are 2 IP addresses in play here.

You have a dynamic IP from the provider, it changes at will, your modem will change with it. This is the IP that floats around in the world and that you will see on websites that register your IP address.

You have a Local IP from your wireless router. The IP that your computer shows on it's wireless connection is a LAN IP and is totally unrelated to the ISP's dynamic IP. Two different numbers, no relation at all. One can be static, one dynamic, both static, etc, will make not one hair of difference for your situation.

Does that help??

 

Thanks Handygal.

It does help, but for the past several years that I've had Comcast as my ISP, when I go to a website like WhatIsMyIP.com, it has shown the exact same IP address.

Some websites display your IP address, and just for privacy reasons I'm uncomfortable with so many years of my IP address being displayed on websites (such as Forums that show your IP), and it is always the same IP address - it has been for years.

I was hoping there was a wireless router I could buy that would alter my IP once in awhile, as it's not really practical to plug my computer into the cable modem just to have a different IP show onliine.

If I just buy a new wireless router, will that one have a different IP address than the one I have now?

 

Sounds like Comcast reserved the right for you to have a dynamic IP but with your modem always on it never changes?

The router will never do this function because the external IP is being assigned between the ISP and the modem. The router is one step too far down the line.

You mention that rebooting the modem will change the IP but that only works for me if I have it unplugged for hours or even more than a day. Eventually someone gets my old IP and I get a new one. I usually have better luck if I unplug it Friday evening and turn it back on Saturday afternoon or later. I don't have cable so you might not have to wait.

Unless you have a smart house or something else internet dependent, you might want to make a habit of turning off your modem when you are away for the weekend. That should get you a new external IP if Comcast truly has you set for dynamic. In fact, I'm going to try to remember to do that myself.

 

I had at my previous address and I believe the lease time on their IP's was 7 days. What that means is that when comcast assigns you and IP, your router will hold that for 7 days before asking to RENEW the IP. What that also means, is that comcast keeps that IP address under your name for the 7 days. So if you unplug your router on day 3, and plug it back in on day 4, you likely will still get the same IP address because comcast remembers it still. Because majority of homes have routers that stay on all the time, most users IP addresses don't change very often, if at all. Since everyone is RENEWing their IP address at unique times, Comcast generally hands out the same IP addresses repeatedly.

From a security perspective, it is only slightly more secure to change your IP address. Without getting too technical, if someone was targeting you specifically, it still would not be too difficult to get your new IP.

Personally, I wish I would get the same IP so I could use my FTP server without having to pay extra.

 

No because the IP address shown is the external (ISP assigned) IP address which you have no control over.

As handygal says, rebooting after a long shutdown of the modem is the only way to get a new ISP assigned IP address if you have a dynamic address, which you probably do.

This is also true as your first line of defense, which you can do anything about, is the router. You can not change any settings in the modem and the ISP would not want you to, since it is set up for their network protocols and procedures.

You can only change security from the router back into your network which you say is just one computer. Having a properly set up software firewall, an effective anti-virus application, malware application and foremost, using safe surfing habits/procedures are your only recourses in security.

chaslang has an excellent thread on how to protect yourself online - http://forums.majorgeeks.com/showthread.php?t=44525 - give it a read.

 

And if your really paranoid (like myself) you can take an old PC and turn it into a hardware firewall using IPCOP, just to add 1 extra layer of protection. :-D

 

Not mention you can add extra problems that may be hard to troubleshoot and diagnose with a second routing device/firewall. Follow chaslangs guide and you should be golden with out adding a second hardware firewall.

 

Agreed, as Coleman said, 1 extra layer of protection means 1 extra point of failure. Unfortunately, as they saying goes, security is never convenient. Chaslangs guide should give you all the protection you need. And always remember, 11) Security starts with you! Be careful what you download and from where!

 

I like that quote. I don't use anti-virus programs. I am behind a firewall but a very limited one. I rarely ever get viruses, and if I do manage to get one, I restore my computer instead of wasting hours trying to remove it, only to find out you didn't. I have a separate partition on my hard drive where I save all my projects, documents, photos, software, and it works like a charm. 99% of malicious content can be avoid simply by being vigilant. Sorry for being a bit off topic