"Cisco" GRE tunnel tunnel

Description: A company's PC1 network segment 192.168.1.0/24 to and B Company PC2 Network segment 172.16.2.0/24 establish GRE tunnel communication

Configuration ideas:
1, R1 and R2 to be able to communicate--R1 and R2 respectively configure default routes to the ISP
2, the new tunnel port, set the IP, the two sides to the same network segment, configure the source is the public network export IP and destination is the other public network export IP
3, at this time both sides tunnel has been established, need to set up a route, PC1 network segment to PC2 network segment, PC2 network segment to PC1 network segment, the next hop address for the peer IP;

The topology diagram is as follows:

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Configuration information:

R1:
Config T
IP Route 0.0.0.0 0.0.0.0 100.1.1.2
int G0/1
No sh
IP Add 100.1.1.1 255.255.255.252
Exit
int F0/1
No sh
IP Add 192.168.1.1 255.255.255.0
Exit
int Tunnel 0
No sh
IP Add 10.10.10.1 255.255.255.0
Tunnel Source 100.1.1.1
Tunnel Destination 200.2.2.2
Tunnel mode GRE IP
Exit
IP Route 172.16.2.0 255.255.255.0 10.10.10.2
Exit

Isp:
Config T
int G0/1
No sh
IP Add 100.1.1.2 255.255.255.252
Exit
int G0/2
No sh
IP Add 200.2.2.1 255.255.255.252
Exit

R3:
Config T
IP Route 0.0.0.0 0.0.0.0 200.2.2.1
int G0/2
No sh
IP Add 200.2.2.2 255.255.255.252
Exit
int F0/1
No sh
IP Add 172.16.2.1 255.255.255.0
Exit
int Tunnel 0
No sh
IP Add 10.10.10.2 255.255.255.0
Tunnel Source 200.2.2.2
Tunnel Destination 100.1.1.1
Tunnel mode GRE IP
Exit
IP route 192.168.1.0 255.255.255.0 10.10.10.2
Exit

Need to see the ping process, can turn on debug, debug IP packet

This article is from the "tommyking" blog, make sure to keep this source http://tommyking.blog.51cto.com/10481841/1916999

"Cisco" GRE tunnel tunnel