I’ve seen this issue twice in as many days – a computer can ping internal and external machines, but cannot browse any websites or use VPN. Skype may work on the LAN but IE will not connect to any websites (if it starts at all) and Outlook won’t connect to Exchange.
Checkpoint and Gotomeeting fail with error messages at logon.
The usual solutions left me scratching my head:
- Link light shows connectivity, so it’s not a hardware problem
- Windows network adapter shows connectivity to network, even recognizes the local domain
- ARP-D * successful, no errors
- Uninstall, reinstall adapters in Device Manager (this is helpful when a VPN adapter corrupts TCP/IP)
- IPCONFIG / FLUSHDNS successful, no errors
- Windows network adapter diagnose (no problems found)
- NETSH INT IP RESET c:\resetlog.txt, successful
- Confirm DNS settings (DNS wasn’t the problem, we can ping external addresses with DNS names)
- Reset IE, no proxies in use
You can probably see which direction this is going (hint: session layer). The problem was higher up the OSI.
NETSH WINSOCK RESET
Remember to run in administrative command prompt. A VPN installation or uninstallation broke Winsock so it needed to be reset.