This is for all Plusnet customers who may be using VPN to connect to their work networks over a Plusnet ADSL line.
Around a week ago Plusnet enabled a firewall for their ADSL customers. They announced that in an e-mail and it was good news. I skimmed over the e-mail and then forgot about it.
Anyway, I tried my Nortel Networks Extranet Client to connect to my work network today on my Plusnet ADSL line. It didn't work. I kept getting 'the remote server is not responding' from the VPN software even though I could ping the switch that it was trying to connect to.
I first thought that a setting on my router had changed. Nope. I then contacted my MIS department and they said everything looks okay at the switch level. I tried my other ADSL line (Nildram) and everything worked fine.
I looked up the error message on Google and eventually found a forum where someone had posted the same error message. A response mentioned the Plusnet firewall. So, I went into the Plusnet Control Panel and noticed that the security level of the Plusnet firewall was set to 'high' (which is the default).
I set it to medium and my VPN software worked.
So, if you're using VPN clients over a Plusnet ADSL line, you need to set the Plusnet firewall to medium of off to get it to work.