I have a strange problem that I need solved ASAP.
We have a Cisco 3000 Concentrator serving as a VPN Server at the office (since the past 2 years running without a problem) end & Clients connect using the software provided by Cisco (Windows NT IPSEC Support Client) after establishing the initial connection clients log on to the network & use Various Applications (Intranet Based, VNC etc) lately in sporadic areas where people are using cable modems only are having problems connecting (connection too slow vnc won’t come up, Web Page of intranet site won’t come up, timeouts etc.) now if the same people use dial-up it’s fine. We called the cable companies to see if the problem was there & they say to upgrade to their business services (which is too expensive).
Through all this what I need to know is that is there some kind of port filtering lately been enabled by the cable companies that restrict access to uncommon or non standard ports?