DSL Router IP Address

[Wayne Suite]

What would be the easiest way to get the DSL Router IP Address?

How does this IP Address relate to the computer IP address which is physically connected to the DSL Router via network cable?

How often does this DSL Router IP Address change?

How would I be able to deternine which IP address belongs to the DSL Router and which belongs to the physically connected computer?

Basic questions for most of you probably, but I am new to this DSL thing and am researching info for a possible project. I am really not looking for code but just pointers such as API's and general knowledge.

Thanks
Wayne.

[Mel Bishop]

1. www.whatismyip.com
2. The same way your U.S. mail address relates to your next door neighbors. It's just an address your router uses to switch data packets.
3. Depends on your ISP. You probably have a dynamic address but you can ask them for a static IP address.
4. Check the DHCP table in your router.

[Scott Turchin]

I th ink you can get a static IP that won't change on DSL but you'd hae to request it.

My IP hasn't changed in a year, I have a website pointing on mine..

As for programatically recovering your IP address you'd have to do an ICMP echo/trace route and recover the IP from the first hop (Your IP will be hop 0)....

[Cliff Nichols]

Traceroute is the way to go, but I can not remember if its the IP as your internal sees it, or if external sees it (Your modem internally may be all 192 addresses, but once you get outside the wall then your external Ip can be read.)

The question is classical and I have asked it often myself...I know my internal Ip, I can see my external IP from other sites, but how in the world to read my External, without leaving my internal??? now that is the question

[Marco Pontello]

The question is classical and I have asked it often myself...I know my internal Ip, I can see my external IP from other sites, but how in the world to read my External, without leaving my internal??? now that is the question

There's always the possibility of asking to your router, via HTTP / TELNET / SNMP. Off course there will be differences between various devices.

But the most simple solution is usually that of simply downloading and URL (lots source examples for that) from a server/site that show the IP of a visitors, and do a minimal parsing of the "page" for that IP. Obviously the URL can also a point to a server that you have control on, using his external / public address, where you may have setup a page that just show the bare IP. In PHP, something as simple as:

showip.php

<? echo getenv('REMOTE_ADDR'); ?>

A script like that will work even on the most basic hosting service with PHP support.
So you GET an URL like http://www.myserver.com/showip.php, and you have just the info you need, in plain text.

Bye!

[John Petty]

If you also control the receiving computer on the net then you just send it a UDP packet. The IP address that the receiving computer will get in the PB UDP RECV statement will show will be the external address of the router.
Tracert will only give you the internal IP of the router