Para ver las conexiones establecidas:

rtr-lbox-c891#sh vpdn
%No active L2TP tunnels
PPTP Tunnel and Session Information Total tunnels 1 sessions 1
LocID Remote Name State Remote Address Port Sessions VPDN Group
 49368 estabd 88.3.31.11 60361 1 VPDN_GROUP_PPTP
LocID RemID TunID Intf Username State Last Chg Uniq ID
 6522 60361 49368 Vi6 lbox\sworks estabd 00:02:42 7

Para eliminar una conexion:

rtr-lbox-c891#clear vpdn tunnel pptp id 49368