I have an odd problem. I use Tik to create a pptp connection between our office and some home users. The cable internet people work fine, however the DSL people cannot pass traffic over the pptp connection. These DSL people have a DSL modem which does the PPPoE authentication on the modem itself and then gives a public IP to whatever is plugged into it. (Our cable internet does not use PPPoE authentication). Both the cable and the DSL are dynamic IP setups.
If I bring the PPPoE connection back to the Tik and set that as the default route, my PPTP connection works perfectly. Does anyone have any idea why having the PPTP connection one hop behind the PPPoE connection would break it? Also, is there another tunnelling protocol where this would not be an issue? I am not exactly attached to the PPTP tunnel, I just arbitrarily chose it, I simply need a VPN of some kind.