Difference between revisions of "Cisco GRE Tunnel"

From Ever changing code
Jump to navigation Jump to search
(Created page with "'''Generic Routing Encapsulation (GRE)''' - RFC 2784 - developed by Cisco is non-secure, stateless (no flow control), site-to-site VPN tunneling protocol. The '''Protocol Type...")
 
 
Line 7: Line 7:
[[File:Gre_tunnel.png|none|left|Gre tunnel]]
[[File:Gre_tunnel.png|none|left|Gre tunnel]]


  R1(config)# interface Tunnel0                              R1(config)# interface Tunnel0     
  R1(config)# interface Tunnel0                              R2(config)# interface Tunnel0     
  R1(config)# tunnel mode gre ip                            R1(config)# tunnel mode gre ip        !tunnel interface is GRE over IP
  R1(config)# tunnel mode gre ip                            R2(config)# tunnel mode gre ip        !tunnel interface is GRE over IP
  R1(config)# ip address 10.1.1.1 255.255.255.252            R1(config)# ip address 10.1.1.2 255.255.255.252   
  R1(config)# ip address 10.1.1.1 255.255.255.252            R2(config)# ip address 10.1.1.2 255.255.255.252   
  R1(config)# tunnel source 209.165.201.1                    R1(config)# tunnel source 198.133.219.87
  R1(config)# tunnel source 209.165.201.1                    R2(config)# tunnel source 198.133.219.87
  R1(config)# tunnel destination 198.133.219.87              R1(config)# tunnel destination 209.165.201.1
  R1(config)# tunnel destination 198.133.219.87              R2(config)# tunnel destination 209.165.201.1
  R1(config)# router ospf 1                                  R1(config)# router ospf 1     
  R1(config)# router ospf 1                                  R2(config)# router ospf 1     
  R1(config-router)# network 10.1.1.1 0.0.0.3 area 0        R1(config-router)# network 10.1.1.1 0.0.0.3 area 0
  R1(config-router)# network 10.1.1.1 0.0.0.3 area 0        R2(config-router)# network 10.1.1.1 0.0.0.3 area 0


= Troubleshooting =
= Troubleshooting =
  show ip interface brief | include Tunnel
  show ip interface brief | include Tunnel
  show interface Tunnel 0
  show interface Tunnel 0

Latest revision as of 23:20, 5 December 2015

Generic Routing Encapsulation (GRE) - RFC 2784 - developed by Cisco is non-secure, stateless (no flow control), site-to-site VPN tunneling protocol. The Protocol Type field holds identifier for a passenger protocol (encapsulated L3 OSI protocol) - defined in RFC 1700 as EtherTypes.

Gre tunnel diagram

Configuration

Gre tunnel
R1(config)# interface Tunnel0                              R2(config)# interface Tunnel0     
R1(config)# tunnel mode gre ip                             R2(config)# tunnel mode gre ip        !tunnel interface is GRE over IP
R1(config)# ip address 10.1.1.1 255.255.255.252            R2(config)# ip address 10.1.1.2 255.255.255.252   
R1(config)# tunnel source 209.165.201.1                    R2(config)# tunnel source 198.133.219.87
R1(config)# tunnel destination 198.133.219.87              R2(config)# tunnel destination 209.165.201.1
R1(config)# router ospf 1                                  R2(config)# router ospf 1     
R1(config-router)# network 10.1.1.1 0.0.0.3 area 0         R2(config-router)# network 10.1.1.1 0.0.0.3 area 0

Troubleshooting

show ip interface brief | include Tunnel
show interface Tunnel 0