本例中只给出一台路由器的配置，另一台路由器的配置只是进行对应性的修改就可以了。

1. Cisco 2600 with GRE Tunnel

Current configuration

!

version 12.0

sevice timestamps debug uptime

sevice timestamps log uptime

sevice password-encryption

!

hostname bluestudy1

!

enable passsword cisco

!

memory-size iomem 25

ip subnet-zero

no ip domain-lookup

!

interface Tunnel0

ip address 172.16.101.1 255.255.255.0

no ip directed-broadcast

ip mtu 1467

tunnel sourece 199.1.1.2

tunnel destination 199.1.2.2

!

interface serial0/0

no ip address

no ip directed-broadcast

encapsulation frame-relay

no ip mroute-cache

frame-relay lmi-type ansi

!

interface serial0/0.1 point-to-point

description connected to internet

ip address 199.1.1.2 255.255.255.248

no ip directed-broadcast

ip nat outside

no arp frame-relay

frame-relay interface-dlci 111

!

!

interface ethernet0/0

ip address 172.16.1.1 255.255.255.0

no ip directed-broadcast

ip nat inside

!

router eigrp 100

network 172.16.0.0

!

router rip

version 2

network 172.16.0.0

no auto-summary

!

ip nat pool bluestudy 199.1.1.3 199.1.1.10 netmask 255.255.255.248

ip nat inside sourece list 2 pool bluestudy overload

ip nat inside sourece static 172.16.1.3 199.1.1.5

ip classless

ip route 0.0.0.0 0.0.0.0 srial0/0.1

ip http server

!

access-list 2 permit 172.16.1.0 0.0.0.255

snmp-server community public RO

!

line con 0

exec-timeout 0 0

password cisco

login

transport input none

line aux 0

line vty 0 4

password cisco

login

!

end