do cable companies block port 1723?
Posted on 2005-05-16
Hi, I have multiple remote users, and more and more of the Cable users (comcast, adelpia) are unable to connect. I worked with many of the users and it seems we have shut off all of there software firewalls, and I can't see any blocking at the router appliance. one of these clients changed over to dsl, and was able to connect (vpn) right after with no other configuration nessissary.
now, when i have them run a port checker on port 1723 (pptp, what the vpn uses) it comes back with the following info
Solicited TCP Packets: PASSED — No TCP packets were received from your system as a direct result of our attempts to elicit some response from any of the ports listed below — they are all either fully stealthed or blocked by your ISP. However . . .
Unsolicited Packets: PASSED — No Internet packets of any sort were received from your system as a side-effect of our attempts to elicit some response from any of the ports listed above. Some questionable personal security systems expose their users by attempting to "counter-probe the prober", thus revealing themselves. But your system remained wisely silent. (Except for the fact that not all of its ports are completely stealthed as shown below.)
Ping Reply: RECEIVED (FAILED) — Your system REPLIED to our Ping (ICMP Echo) requests, making it visible on the Internet. Most personal firewalls can be configured to block, drop, and ignore such ping requests in order to better hide systems from hackers. This is highly recommended since "Ping" is among the oldest and most common methods used to locate systems prior to further exploitation.
if you need to know the port scanner Ill post it. the cable companies say they dont block that port, but I dont think Im talking to anything past tier 1 support, so they seem to deny everything. I just want an awnser so i can tell the clients a hard answer.
thanks and any help is greatly appreciated.