Put a (Win)Sock in it !

A client on holiday wanting remote access to the office and internet browsing asked me to check out their tcpip settings so that they could pick up internet access on wireless card built into a Dell Vostro. So dutifully we tested the access on a BT Broadband wireless router – setting the wireless adapter to DHCP to get an address and dns settings from the router when at their holiday location. This worked flawlessly….

So I was surprised to get a call from the client on site with no internet access. They had however got a connection to the wireless router – and were able to ping it. Attempts to ping known ip addresses on the internet failed as did all attempts to browse via IE or use Skype or VNC !!

A test at a local “Starbucks” wireless cafe with no ssid or settings required gave the same result. A connection but nothing more than pinging the router/access point was possible.

So the suggestion was that the wireless hardware had a fault – so we got the portable wired directly to the router and picked up a dhcp address – exactly same result – able to ping router but nothing else – no nslookup – no tracert possible.

At this point I was sure that we had a software issue but the culprit wasn’t clear – a final check for firewalls or other security software causing problems threw up nothing. Then I wondered if the TCPIP stack was still working as expected.

Getting the client to run

netsh winsock reset catalog

from a command prompt and then reboot still had no effect

so going for

netsh int ip reset c:reset.log

and a reboot got them online and working with all the applications they required. Result !!

So the thing that seemed unusual here was that ping worked to ping the router on its private internal address but then was not able to access remote (non private) ip addresses.