Can't make PPTP VPN Connection via 4G Hotspot

Question

I am trying to connect to a known VPN. Through a normal connection (i.e., wireless -> ISP) it works. However, via my 4G modem, I cannot connect. Error message is here

Apr  1 11:42:28 Dans-15 pppd[2546]: pppd 2.4.2 (Apple version 412.4) started by example, uid 501
Apr  1 11:42:28 Dans-15 pppd[2546]: PPTP connecting to server 'vpn.example.com' (vpn.example.com)...
Apr  1 11:42:29 Dans-15 pppd[2546]: PPTP connection established.
Apr  1 11:42:29 Dans-15 pppd[2546]: Connect: ppp0 <--> socket[34:17]
Apr  1 11:42:59 Dans-15 pppd[2546]: LCP: timeout sending Config-Requests
Apr  1 11:42:59 Dans-15 pppd[2546]: Connection terminated.
Apr  1 11:42:59 Dans-15 pppd[2546]: PPTP disconnecting...
Apr  1 11:42:59 Dans-15 pppd[2546]: PPTP disconnected

How can I examine the problem further? How can I find out more detail about the LCP: timeout?

Computer is running OSX 10.6.something. Same problem happens via iOS systems, too.

Answer 1

Your 4G provider likely blocks port 1723 (or possibly won't forward GRE packets for you) unless you purchase some sort of "business class" tier service.

Another thing I thought of is that your 4G connection probably uses PPP or PPPoE, and I don't know if you can use GRE with PPP.

Answer 2

The real answer is: if you have the Samsung 4G hotspot from Verizon and must use a PPTP VPN, call Verizon and insist that they swap your hotspot for the Novatel.