Дополню-
вот ссылка на первоисточник, а именно на сайт циски
http://www.cisco.com/warp/public/471/l2 ... k-cit.html
по этой ссылке пример концигурации l2tp, ниже вырезка по этой ссылке. Делали на циске 1 в 1, не работает.
hostname fifi
!
username l2tp-w2k password 0 ww
!--- This is the password for the Windows 2000 client.
!--- With AAA, the username and password can be offloaded to the external
!--- AAA server.
!
vpdn enable
!--- Activates VPDN.
!
vpdn-group l2tp-w2k
!--- This is the default L2TP VPDN group.
accept-dialin
protocol l2tp
!--- This allows L2TP on this VPDN group.
virtual-template 1
!--- Use virtual-template 1 for the virtual-interface configuration.
no l2tp tunnel authentication
!--- The L2TP tunnel is not authenticated.
!--- Tunnel authentication is not needed because the client will be
!--- authenticated using PPP CHAP/PAP. Keep in mind that the client is the
!--- only user of the tunnel, so client authentication is sufficient.
!
interface loopback 0
ip address 1.1.1.1 255.255.255.255
!
interface Ethernet1/0
ip address 200.0.0.14 255.255.255.0
ip router isis
duplex half
tag-switching ip
!
interface Virtual-Template1
!--- Virtual-Template interface specified in the vpdn-group configuration.
ip unnumbered Loopback0
peer default ip address pool pptp
!--- IP address for the client obtained from IP pool named pptp (defined below).
ppp authentication chap
!
ip local pool pptp 1.100.0.1 1.100.0.10
!--- This defines the "Internal" IP address pool (named pptp) for the client.
ip route 199.0.0.0 255.255.255.0 200.0.0.45