Public and Private IP Address on router?

mathie

Hi
Ive a /netopia router through Eircom.
How can I make sure my private ip address (which i find out via using 'cmd' and ipconfig) is the same as my public one (http://www.whatismyip.com/)

And also that it doesnt change every time the router is reset?

thanks
m

PogMoThoin

You can't, its called nat, its what the router is doing
http://en.wikipedia.org/wiki/Network_address_translation
http://www.howstuffworks.com/nat.htm

Your public ip will usually change dynamically (depending on service), but most providers offer static ip addresses for an extra fee, ie it won't change, Your router/modem would get the same one everytime

Feelgood

mathie wrote: »

Hi
Ive a /netopia router through Eircom.
How can I make sure my private ip address (which i find out via using 'cmd' and ipconfig) is the same as my public one (http://www.whatismyip.com/)

And also that it doesnt change every time the router is reset?

thanks
m

Hey Mathie,

PogMoThoin is right your router translates your public to private, what are you trying to figure out exactly or what issue are you having?.

vibe666

ditto to what has already been said.

if you wanted your PC to have a public IP address you *could* change your router settings to make it a simple DSL modem to give your PC your public IP address, but trust me that you REALLY REALLY don't want to. ever.

your router is there to protect you from the big bad nasty internet and part and parcel of that is hiding you from all and sundry online using NAT to mask your actual private IP address behind the router and keeping itself and it's firewall in between you and the public IP address that your ISP gives you. that simple layer of protection will keep you safe from the overwhelming majority of direct online attacks and there is no sensible reason to get rid of it.

if you're looking to access something on your home PC remotely, you can set up a free account with http://www.dyndns.com/ and get a (sub)domain name that will stay the same and automatically be re-pointed to your IP address every time it changes, so you don't ever even need to know what your IP address even is.

combine that with some simple port forwarding on your router and you can access pretty much any network related service remotely over the internet using a friendly domain name in the format of http://you.dyndns.com (or any one of dozens of other sub-domains given out free by dyndns.com).

i use mine to access my home PC from work via RDP over SSH and also a file server and a bunch of other stuff as and when the need arises. online gaming, VPN's, web proxy, web servers or pretty much anything else you can think of.

it might sound complicated at first, but once you understand the basics of it, it's only a few simple steps to get up and running initially and then it's just a few more simple steps to add more features as you need them.

jor el

mathie wrote: »

And also that it doesnt change every time the router is reset?

Although putting the router in bridge mode (modem only, no routing as vibe666 said) will make your computer IP the public IP, keeping it static is something you cannot do, unless the ISP can provide a static IP to you. You really don't want to do any of this though. You'll also only be able to have 1 computer connected to the Internet. Your Wifi network will be gone, and you won't be able to connect more than 1 via Ethernet cable too.

My guess is you want to run a server from home, very bad idea, and against every residential ISP's T&Cs. Unless your security is top notch, you don't want to be opening yourself up to the Internet like that, and you especially don't want to disable the router function of the modem if you are doing this.