Computer Help forum

General discussion

Any idea why computer IP address would change?

by wgrayson / September 9, 2010 7:56 AM PDT

About 6 or 7 months ago, I successfully set up my home PC (running Windows 7 Pro) to work with Remote Desktop Connection. I figured out all the hard stuff --- how to access it via the router's IP address, how to configure both the router AND the firewall to open the appropriate ports, etc.

My actual PC behind the router and the firewall had an IP address of of something like (this one of the default IP addresses given to a PC as part of a network). This IP address needs to be plugged into the router's settings. While I was away on a trip I was unable to access my PC remotely. When I returned to troubleshoot the issue, I discovered the IP address had changed to (note the last digit change). Ummmmmmmmmm, any idea how an IP address could have changed?

My wife informed me that on one day only she was having connectivity issues with the internet, so I instructed her on resetting both the cable modem and router --- the simple way of unplugging and replugging both. Could this have anything to do with it? RDC is working fine now, but I'm just curious.

Thanks in advance,


Post a reply
Discussion is locked
You are posting a reply to: Any idea why computer IP address would change?
The posting of advertisements, profanity, or personal attacks is prohibited. Please refer to our CNET Forums policies for details. All submitted content is subject to our Terms of Use.
Track this discussion and email me when there are updates

If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.

You are reporting the following post: Any idea why computer IP address would change?
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.
Collapse -
Resetting The Router Did It..
by Grif Thomas Forum moderator / September 9, 2010 9:07 AM PDT

As such, the computer is recognized as if new and a new IP address is released from the router to the computer..

Hope this helps.


Collapse -
Grif is correct
by lacsr / September 9, 2010 9:16 PM PDT

If the possibility of it getting a different IP address from the router will cause further problems, set up the router is given the computer in question a fixed IP address, instead of auto assigned. Depending on the router, it usually is easy to do.

Collapse -
by andersonalexer / September 10, 2010 5:18 AM PDT

do you use dhcp server?

Collapse -
Not sure if I'm using a DHCP server
by wgrayson / September 10, 2010 2:03 PM PDT

I have a typical home office setup with a cable modem provided by my ISP connected to a standard Linksys G router.

Collapse -
DHCP Servers is the key
by warrencharlot / September 10, 2010 3:33 PM PDT

If you are using third party devices that acts as a DHCP server such as routers then your IP address may change especially when you try to turn it off and on or if you try to change it manually in some cases. Modems are not DHCP servers but some modems are actually modem-routers that is considered a DHCP server. Your phone or ISP server may provide you with a modem without telling you that it is actually a modem-router which changes your IP.

Popular Forums
Computer Help 49,613 discussions
Computer Newbies 10,349 discussions
Laptops 19,436 discussions
Security 30,426 discussions
TVs & Home Theaters 20,308 discussions
Windows 10 360 discussions
Phones 15,802 discussions
Windows 7 7,351 discussions
Networking & Wireless 14,641 discussions


CNET bought a house!

Take a look inside the house where we will be testing connected locks, thermostats and other smart home products so we can tell a complete story.