I have a customer who has a Mikrotik router for many uses, including using it as a VPN concentrator for Sprint wireless card remote clients (using PPTP VPN). Every few hours, sometimes every few minutes clients have disconnects, and sometimes they can’t reconnect right away. I have been over the config, changing keep-alives, watching clients, and most of the time a non-wireless remote client stays connected continuously. I upgraded from 2.8.28 to 2.9.13 and still have the same problem. 3 other local agencies use the same type of Sprint AirCard 550 wireless cards with other VPN concentrator vendors (Cisco mostly) and have no disconnect problems, so the people in charge of this agency are very upset and are blaming the fact they have a software router instead of a Cisco router.
I think it’s the Sprint AirCards, but then I got to thinking maybe the Cisco VPN client is using L2TP/IPSEC instead of PPTP, but I can’t figure out even after looking at the docs how to make IPSEC work, and whether that would even matter. I was thinking it was because PPTP might break under bad links easier than L2TP/IPSEC, but who knows…
Any ideas?