1.1 Introduction to GRE...........................................................................................................................................2

1.2 GRE Features Supported by the AR1200...........................................................................................................2

1.3 Configuring GRE................................................................................................................................................3

1.3.1 Establishing the Configuration Task.........................................................................................................3

1.3.2 Configuring a Tunnel Interface.................................................................................................................4

1.3.3 Configuring Routes for the Tunnel............................................................................................................5

1.3.4 (Optional) Configuring GRE Security Options.........................................................................................6

1.3.5 Checking the Configuration.......................................................................................................................7

1.4 Configuring a GRE Tunnel Between CE and PE...............................................................................................8

1.4.1 Establishing the Configuration Task.........................................................................................................8

1.4.2 Configuring the GRE Tunnel Interface on CE..........................................................................................9

1.4.3 Configuring the GRE Tunnel Interface on PE.........................................................................................10

1.4.4 Binding the GRE Tunnel with the VPN to Which CE belongs on PE....................................................12

1.4.5 Checking the Configuration.....................................................................................................................12

1.5 Configuring the Keepalive Function................................................................................................................13

1.5.1 Establishing the Configuration Task.......................................................................................................13

1.5.2 Enabling the Keepalive Function............................................................................................................14

1.5.3 Checking the Configuration.....................................................................................................................15

1.6 Maintaining GRE..............................................................................................................................................16

1.6.1 Resetting the Statistics of a Tunnel Interface..........................................................................................16

1.6.2 Monitoring the Running Status of GRE..................................................................................................16

1.6.3 Debugging GRE......................................................................................................................................17

1.7 Configuration Examples...................................................................................................................................17

1.7.1 Example for Configuring a Static Route for GRE...................................................................................17

1.7.2 Example for Configuring a Dynamic Routing Protocol for GRE...........................................................21

1.7.3 Example for Configuring a GRE Tunnel to Transmit VPN Multicast Data Encrypted with IPSec........25

1.7.4 Example for Configuring the CE to Access a VPN Through a GRE Tunnel of the Public Network

..........................................................................................................................................................................31

1.7.5 Example for Configuring the Keepalive Function for GRE....................................................................38

2 MCE Configuration.....................................................................................................................41

2.1 Introduction to MCE.........................................................................................................................................42

Issue 01 (2012-04-20)

Huawei Proprietary and Confidential

Contents