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New Visitor
Posts: 5
Registered: ‎04-08-2006

VPN access using comcast.net

I periodically have a problem accessing my work intranet via VPN from home. Comcast is my internet provider. I was just able to connect via wireless at my community library, so I suspect the problem is with Comcast. It is sporadic--sometimes no problem at any time of day or night. It seems to be more frequent on the weekends. Any ideas?
Bronze Problem Solver
Posts: 5,958
Registered: ‎03-12-2004

Re: VPN access using comcast.net

> I periodically have a problem accessing my work
> intranet via VPN from home. Comcast is my internet
> provider. I was just able to connect via wireless at
> my community library, so I suspect the problem is
> with Comcast. It is sporadic--sometimes no problem at
> any time of day or night. It seems to be more
> frequent on the weekends. Any ideas?

VPN using a cisco client works without incident for me connecting to my office through comcast.

It probably doesn't help you much to know that other than as an indication that there is no inherent problem using VPN connections over comcast.
New Visitor
Posts: 5
Registered: ‎04-08-2006

Re: VPN access using comcast.net

Thanks. At least 50% of the time I also have no problem. I'm having the problem now, and wish I could figure out what happens differently between when it is fine and when not.
Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: VPN access using comcast.net

I have used several VPN's in the past, mostly SonicWall and Checkpoint. No issues that were not casued by user error :smileyhappy:.

You say you are using wireless, does that mean you are using a router? If so, what kind? Have you upgraded the firmware?
New Visitor
Posts: 5
Registered: ‎04-08-2006

Re: VPN access using comcast.net

Hmmm...not sure what you mean. I normally access VPN using comcast. I do have a wireless card and sometimes use it (but not at home because I don't have wireless capability available). I just wanted to check whether my access to VPN today was a comcast issue or something going on at work--that's why I went to the library to use their wireless. What happened is that I could use VPN to get to my work intranet if my internet access was wireless. That is successful. However, not if the internet access is via comcast cable. Thus, wouldn't you think it was a comcast problem?

I tried powercycling and check the ports (suggestions from comcast help), but it's still not working.
Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: VPN access using comcast.net

It's probably not a Comcast problem, more likely a setup issue of some kind. Try turning off your firewall as a test and see if that helps. When you connect at the library, your IP is different and your firewall might not be interfering on that interface.

What kind of VPN are we talking about here? Have you talked to your IT folks to see if the block is on their end?
Email Expert
Posts: 18,241
Registered: ‎04-27-2004

Re: VPN access using comcast.net

Do you have a router at home? Make sure it has VPN pass-through enabled, if necessary. You also might need to enable NAT Traversal (sometimes called UDP Encapsulation) in the VPN client.
Connection Expert
EG
Posts: 43,056
Registered: ‎12-24-2003

Re: VPN access using comcast.net

>>Comcast. It is sporadic--sometimes no problem at any time of day or night. It seems to be more frequent on the weekends. Any ideas?

Might you be losing your entire connection to Comcast ?

Can you browse to webpages when this happens ?

What are the modem's lights doing when this issue occurs ?

What does the modem's error log look like ?
New Visitor
Posts: 5
Registered: ‎04-08-2006

Re: VPN access using comcast.net

Thank you to everyone who replied. I now have some ideas to pursue, including finding another internet service provider (connecting to my work intranet from home is a must at this time)!

Some answers:
1) When VPN doesn't work, all other internet connectivity is fine
2) The lights on my modem don't flash when this problem occurs (but I haven't checked the lights when VPN is fine--that I will do if it EVER comes back)
3) I did log a help ticket with my work helpdesk, but I hold no hope there
4) If the settings change back and forth, when sometimes it works and sometimes it doesn't, why, why, why?

Again, thank you to all who took the time to reply. I really appreciate it. I am now obsessed with getting this corrected (stupid, right? but "obsessed"!).
Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: VPN access using comcast.net

Good luck. There's not much we can do without further information. Since many of us have used VPN's on Comcast without issue and Comcast has stated they don't interfere in VPN traffic, the likelyhood that this is a Comcast problem is slim to none.

Most VPN clients keep a log of some sort, it would be instructive to view that log when a problem happens and see what the client thinks is not working. That will help you narrow it down.
New Visitor
Posts: 5
Registered: ‎04-08-2006

Re: VPN access using comcast.net: Update

My work technical support person finally decided to try to uninstall my VPN version and install a more current version. That seems to have corrected the problem (so far, anyway). We're not sure why, but I have not had a connection problem since he did this install. I just thought I'd provide this update.
Networking Expert
Baric
Posts: 24,238
Registered: ‎07-28-2003

Re: VPN access using comcast.net: Update

I hate these kinds of solutions, it leaves you wondering what the real problem was. But if it works (and resinstalling seems to work for many different kinds of software problem), that's the important part.