MS PPTP and SB5100 modem

[MarkR800]

Hi,

Moved this over from the TCP/IP forum.....

To cut a very long story short, it seems that Motorola SURFboard 5100 broadband cable modems are incapable of passing Microsoft PPTP connections. Can anyone prove me wrong on this one?

I have elimated everything to do with firewalls, etc. and have also had it confirmed on another two 5100s using the same ISP that PPTP connections fail. It is not related to the ISP, as a Motorola SURFboard 4100 cable modem via the same ISP works fine (verified in two separate locations). The 5100 modem will pass VPN connections using VPN client software (e.g. Cisco, which used port 10000) but it will seemingly not pass MS PPTP (port 1723) or IPSec connections.

Has anyone had any sucess in doing this? The ISP refuses to comment on VPNs other than saying they allow them, and Motorola have discontinued support for the 5100 and state that queries should be referred to the ISP.....so basically a big circle where no-one is interested in helping.

Cheers....

 

[Derek5100]

I appear to have the same problem. My remote VPN (PPTP) connection no longer works after I changed from an older 3COM cable modem to a Motorola Surfboard 5101. I can take my desktop computer and laptop to another ISP location using a Surfboard 4200 and everything is fine. Motorola says it is the ISP. The ISP says it is a VPN setup problem. Has anyone had this confirmed by either an ISP or Motorola?

 

[pronet74]

I have a SB5100 here at work and a 5100 at home and my VPN does work fine. Sorry to break the bad news. Perhaps you got a bad batch of modems?

I'm using MS VPN (my xp machine at home connects to my windows 2000 server here at work). All I needed to do was forward port 1723 to the windows 2000 server, and enable pptp vpn (I have a linksys befsx41).

It's something with your ISP/Modem combination.

 

[Derek5100]

We have someone else at our office, who uses a different ISP but now has the same modem after his ISP switched him to a Motorola SurfBoard 5100. His remote VPN connection worked with his older modem.

It has us stumped. ISP says it isn't their issue and Motorola tech support told me I would have to buy a router.

FYI - at the office end, we use a Dlink DI-804HV VPN router on a DSL connection. We have this setup at two office locations and this is the first issue we have had with remote access in the past two years.