Lost Internet access on some machines 1

[Gersen]

howdy all,

We have a Win 2000 domain that had been using an ISA Server as it's Internet gateway. We just switched over to DSL and a hardware firewall. I went through all the workstations and uninstalled Microsoft Proxy Client, then changed the browser settings, then set the system's gateway address to point to the firewall's internal address. This gave me access to the Internet on 6 out of 9 machines.

The last 3 refuse to connect to the Internet in any way. I've been through the TCP settings, checked DNS and WINS, pinged the firewall's internal and external interfaces, but simply can not connect. The TCP settings and browser settings are the same on all machines, and they run Win 2000 Pro. They are not yet all at the same Service Pack, but that's not a common thread amongst the problem machines.

These machines can resolve names, because they point to our internal DNS server which forwards DNS requests to our ISP, but if I open a web browser, the status line shows that it's trying to open the site by IP address, and it eventually times out. Neither can any other Internet application connect from these 3 machines.

If you can supply any info, or diagnostic suggestions, both I and the business's owner thank you in advance.

Note: these machines are virus free and current on security patches.

 

[SpotLizard]

Gersen,

I would try flushing the workstation's local DNS resolver cache (ipconfig /flushdns), then forcing registration (ipconfig /registerdns).

Use the pathping command to try and ping an external address (either ip or FQDN). This can take several minutes but will give you some comprehensive stats, including packet loss. The pathping command is typed from a command prompt and takes the form pathping

http://www.yahoo.com

etc.

If you are running DHCP have you changed DHCP servers recently ? If your DNS servers are configured to accept secure updates then the workstation owns the Host (A) record and the DHCP server owns the PTR record in the reverse lookup zone. Changing/moving DHCP services creates a problem because although the workstation still owns the Host record the new DHCP server has no ownership of the PTR record. Easiest solution here would probably be to manually delete the workstation's Host and PTR records in DNS, then run ipconfig/registerdns.

Hope this helps.

SL

 

[Gersen]

SL,

Thanks for your input. This was resolved as an issue with our firewall's licensing. We're back in business.