a move from adsl to cable and my vpn is broken

[dninja]

I've just moved across from adsl to virgin cable and my vpn connection to a client I do occasional support for is broken.

Short background, I have two linux boxes and a windows box, all used to be capable of connecting via pptp to the client. Since the move, none of the boxes are able to connect.

The TCP connection is made ok, on the windows pc, the dialogue claims to be sending the username and password but it then times out with a 721 error, on the linux box a packet sniff shows that we are talking to each other. Their IT guy watching the logs says that he sees me connect and then his side tries all the authentication methods before giving up and causing a timeout.

Someone suggested that it could be the cable modem intercepting some of the VPN traffic as it has some kind of built in vpn server.

I've opened port 1723 on my firewall to forward all traffic through to one of the boxes, that doesn't help.

Has anyone else had this problem or can anyone suggest anything else to try?

[MovedGoalPosts]

:welcome: to Cable Forum :tu:

I doubt it is anything on the cable modem that is causing this - I use VPN regularly to my office over virgin media without difficulty. VPN seems to be one of those things that either works fine or throws a major wobbly.

Are you using a router anywhere, or is your client? Maybe between you something isn't quite right. Did you have to change anything significant in your network to get online with cable?

[AbyssUnderground]

Did you change router during the change from adsl to cable? If so you might need to open ports or disable its firewall.

[dninja]

The client hasn't changed anything and their IT guy says the he can connect in from his office so their end seems to be ok. In the move I have changed the internal router from an adsl modem router to a normal router running openwrt. Obviously there is also now a cable modem in the line which wasn't there before. My external IP has changed but the client swears that there is no IP restrictions. My internal network and IP ranges have all stayed the same.

I've got openwrt running on the router which is plugged directly into the modem. I've just installed the pptp client on that and still no luck. The error I'm getting is

LCP: timeout sending Config-Requests

What ports would need to be open to make a vpn connection outwards? Give me some numbers and I'll start opening things!

[MovedGoalPosts]

You've changed the router? Are you sure it's one that supports VPN passthrough?

You can always prove it's something to do with the router by connecting one PC direct to the modem, disconnecting the router during that trial and rebooting the modem.

[dninja]

I've tried making the connection directly from the router and that didn't work.

The router is running openwrt which is a version of linux so it is setup just like an ordinary linux setup. It definitely supports vpns.

I may try a direct connection if I don't get any luck soon, I just don't fancy pulling all the cabling out if I don't need to.

[tweetiepooh]

I too use VPN via Belkin router and both STB and SACM. Problems have always been at the target end.
Once the VPN concentrator cause issues. This gave no connection.
The next my account had been locked. As per good practices there is no indication on client end why but I did get a login prompt.
If you are using the CISCO client you can swithch on logging and put level at highest. This may give an indication of where the issue is.
Also worth checking is any local firewall that may still have setting for old setup but since internally there is no change this seems less likely.

[dninja]

The IT guy can connect ok so he reckons it is my side. As I've changed and they haven't I agree but I think that all is ok.

I'm not sure what the server side is but with full debuging it runs through all the authentication methods and then gives up.

[Mr K]

Don't know if this is connected but I had problems with a Belkin router with NTL/Virgin and VPN pass through, it kept dropping connection. Switched to a wired Linksys befsr41 router which works fine.