/dev/sppptun
The /dev/sppptun pseudo-driver provides an interface for tunneling PPP sessions. This interface provides PPP over Ethernet (PPPoE) service with Solaris PPP.
pppoec(1M), pppoed(1M), sppptun(1M)
RFC 2516 -- A Method for Transmitting PPP Over Ethernet (PPPoE). Mamakos, et. al. February 1999.