А каким образом ты ставил xl2tpd? И нормальный текст ошибки можешь привести?
root@stas-desktop:/home/stas# xl2tpd -D
xl2tpd[3175]: init_network: Unable to bind socket: Address already in use. Terminating.
root@stas-desktop:/home/stas# killall xl2tpd
root@stas-desktop:/home/stas# xl2tpd -D
xl2tpd[3177]: setsockopt recvref: Protocol not available
xl2tpd[3177]: L2TP kernel support not detected.
xl2tpd[3177]: xl2tpd version xl2tpd-1.2.0 started on stas-desktop PID:3177
xl2tpd[3177]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc.
xl2tpd[3177]: Forked by Scott Balmos and David Stipp, (C) 2001
xl2tpd[3177]: Inherited by Jeff McAdams, (C) 2002
xl2tpd[3177]: Forked again by Xelerance (
www.xelerance.com) (C) 2006
xl2tpd[3177]: Listening on IP address 0.0.0.0, port 1701