Unable To Connect To Internet When Connecting To LAN Is OK

Sometimes you may find that you can connect to your local network yet not have access to the internet.

Beyond the normal firewall and anti-virus tests, here are two other slightly more obscure items to check:

1) DNS – go to the CMD line and type in ipconfig/displaydns. This will show your local DNS cache. In some cases the DNS values are either corrupted or incorrect.

To clear the local DNS, type in ipconfig/flushdns

If flushing the DNS doesn’t solve the problem, you can disable and / or restart the DNS caching with these commands:

net stop dnscache
net start dnscache

2) ARP – This is the Address Resolution Protocol and it binds the IP with a physical MAC. You can see the values by typing in at the cmd line, arp -a

If you see any odd machine addresses, like 000-000-000, then you may have to patch the ARP table by using the arp -d and arp -s commands.