Nagios on Slackware 12.1, NSClient on XP. Getting an error

I followed this guide to install nsclient: nagios.sourceforge.net/docs/3_0/ … ndows.html

I followed this for the most part to install Nagios: nagios.sourceforge.net/docs/3_0/ … nsuse.html

Nagios works and shows the linux box its running on. It shows any windows pcs as being down. I get this error in my nsclient log:

“Read on socket failed: recv returned SOCKET_ERROR: 10054: An existing connection was forcibly closed by the remote host.”

I can ping the Nagios server from that windows PC… but I cannot ping the windows PC from the Nagios server.

Any ideas?

What version of Windows do you have? Did you check firewall settings on your Windows machine or tried to turn off firewall?