interface loopback1
 ip addr 10.99.2.1 255.255.255.255
ip local pool p1 10.99.1.2 10.99.1.254
ip local pool p2 10.99.2.2 10.99.2.254
service gprs ggsn
gprs access-point-list apl
  access-point 1
   access-point-name internet
   ip-address-pool local p1
interface Virtual-Template1
 ip unnumbered fastEthernet0/0
 encapsulation gtp
 gprs access-point-list apl
interface Virtual-Template2
 ip unnumbered loopback1
 encapsulation ppp
 peer default ip address pool p2
gprs gtp ppp vtemplate 2