It is the same application l2tpd but maintained by Xelerance Corporation.
That was the reason, I switched to xl2tpd application. I didn’t want to play with kernel that time. And when I tried to install openl2tpd on Centos 5, it asked to enable the L2TP support on kernel. I also had the option of openl2tpd, I tried this on Fedora 8 Linux but there is some bug on fedora 8’s pppd, which stopped me to use that. For VPN application, I use the combination to two applications. I wanted to configure the VPN for some old devices that does support only L2TP VPN. But my requirement could solve by L2TP only. Also, I think no one is using L2TP VPN nowadays. In Linux, you can find so many different applications to build a L2TP server but there is no proper documentation for this. For theoretical information on L2TP you can visit its Wiki.
It doesn’t have any encryption, but we can encrypt the L2TP packets by using it with IPSec. It uses the UDP port 1701 to communicate. L2TP (Layer 2 Tunneling Protocol) is a tunneling protocol used for VPNs.
