PC connects from different locations, but not from home
Posted on 2004-08-24
Dell Dimension 4500
Windows XP Home, Internet Explorer 6.0
Customer unable to connect via ADSL to the Internet (modem only, no router).Upon inspection found the following:
- ADSL properly configured for dynamic addressing.
- Ipconfig revealed that it was pulling an ip (22.214.171.124) which is part of the ISP's range of ip's.
- PC couldn't connect or ping anything.
- Ipconfig/release and ipconfig/renew would not clear this ip. Performing an ipconfig/release and then shutting off the pc overnight and renewing the ip the next day still resulted in pulling the same ip and the connection would continue to fail.
Ran antivirus and spyware scans, reset tcp/ip stack, deleted and reinstalled all network-related stuff, etc., etc. Still no joy.
Now here is what is bizarre:
- I took this pc back to my shop and connected it to my ADSL connection and it pulled a new ip and connected immediately using the customer's ADSL modem.
- I then took the pc to the ISP's office and connected directly to their equipment and again it pulled a new ip and connected immediately.
- Returned to client's premises and reconnected pc, but it reverted to pulling the original ip and failed to connect.
- Replaced the ADSL modem and it still pulled the same ip and failed to connect.
- Called ISP tech support and had them monitor the connection as I attempted to connect. According to tech support, it was the client's pc that was requesting this ip, but the server refused to assign it (probably because it was in use).
- ISP put in a trouble ticket to the telco. Telco responded by rebinding the path and eventually changing to a different port. Still no resolve.
- I brought in my own test PC and connected it to client's ADSL equipment on their premises. My pc pulled a different ip and connected successfully.
How can this customer's pc pull new ip's and connect fine from different locations, but pull the same old ip and fail to connect only when attempting to connect from home???