H3C S12500R Switch Router Series
GRE with OSPF Configuration Examples

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The information in this document is subject to change without notice.

 

Contents

Introduction· 1

Prerequisites· 1

Example: Configuring GRE with OSPF· 1

Network configuration· 1

Software versions used· 2

Restrictions and guidelines· 2

Procedures· 2

Configuring Device A· 2

Configuring Device B· 3

Configuring Device C· 4

Verifying the configuration· 5

Configuration files· 6

Related documentation· 8

 

Introduction

This document provides GRE with OSPF configuration examples.

Prerequisites

The configuration examples in this document were created and verified in a lab environment, and all the devices were started with the factory default configuration. When you are working on a live network, make sure you understand the potential impact of every command on your network.

This document assumes that you have basic knowledge of GRE and OSPF.

Example: Configuring GRE with OSPF

Network configuration

As shown in Figure 1, Device A is the gateway of the headquarters. Device B and Device C are the gateways of Branch 1 and Branch 2, respectively. The gateways have obtained public IP addresses from an ISP and can communicate with one another. Configure GRE with OSPF to meet the following requirements:

·     The headquarters and the branches communicate with one another through the GRE tunnels established between the headquarters and the branches.

·     The gateways learn the routes reaching the destination networks through the tunnel interfaces.

Figure 1 Network diagram

 

 

Table 1 Interface and IP address assignment

Device	Interface	IP address	Device	Interface	IP address
Device A	HGE1/0/1	191.2.1.1/24	Device B	HGE1/0/1	191.3.1.1/24
	HGE1/0/2	10.1.1.1/24		HGE1/0/2	10.7.1.1/24
	Tunnel1	10.5.1.1/24		Tunnel1	10.5.1.2/24
	Tunnel2	10.6.1.1/24
Device C	HGE1/0/1	191.4.1.1/24
	HGE1/0/2	10.8.1.1/24
	Tunnel2	10.6.1.2/24

 

Software versions used

This configuration example was created and verified on Release 3606.

Restrictions and guidelines

Encapsulated packets cannot be forwarded on Layer 3 according to the destination IP addresses and routing tables. You must create a service loopback group of the tunnel service type to loop encapsulated packets back to the forwarding module for Layer 3 forwarding.

By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

Procedures

Before configuring GRE and OSPF, configure an IPv4 routing protocol on the gateways so that they can reach one another. (Details not shown.)

Configuring Device A

# Configure HundredGigE 1/0/1.

<DeviceA> system-view

[DeviceA] interface hundredgige 1/0/1

[DeviceA-HundredGigE1/0/1] ip address 191.2.1.1 255.255.255.0

[DeviceA-HundredGigE1/0/1] quit

# Configure other interfaces in the same way HundredGigE 1/0/1 is configured. (Details not shown.)

# Create service loopback group 1, and specify its service type as Tunnel.

[DeviceA] service-loopback group 1 type tunnel

# Add HundredGigE 1/0/3 to service loopback group 1.

[DeviceA] interface HundredGigE 1/0/3

[DeviceA-HundredGigE1/0/3] port link-mode bridge

[DeviceA-HundredGigE1/0/3] port service-loopback group 1

[DeviceA-HundredGigE1/0/3] quit

# Create a tunnel interface Tunnel 1, and specify the tunnel mode as GRE/IPv4.

[DeviceA] interface tunnel 1 mode gre

# Configure an IP address for the tunnel interface Tunnel 1.

[DeviceA-Tunnel1] ip address 10.5.1.1 24

# Configure the source interface of the tunnel interface Tunnel 1 as HundredGigE 1/0/1.

[DeviceA-Tunnel1] source hundredgige 1/0/1

# Configure the destination address of the tunnel interface Tunnel 1 as the IP address of HundredGigE 1/0/1 on Device B.

[DeviceA-Tunnel1] destination 191.3.1.1

[DeviceA-Tunnel1] quit

# Create a tunnel interface Tunnel 2, and specify the tunnel mode as GRE/IPv4.

[DeviceA] interface tunnel 2 mode gre

# Configure an IP address for the tunnel interface Tunnel 2.

[DeviceA-Tunnel2] ip address 10.6.1.1 24

# Configure the source interface of the tunnel interface Tunnel 2 as HundredGigE 1/0/1.

[DeviceA-Tunnel2] source hundredgige 1/0/1

# Configure the destination address of the tunnel interface Tunnel 2 as the IP address of HundredGigE 1/0/1 on Device C.

[DeviceA-Tunnel2] destination 191.4.1.1

[DeviceA-Tunnel2] quit

# Configure the OSPF router ID as 10.6.1.1.

[DeviceA] router id  10.6.1.1

# Enable OSPF process 1.

[DeviceA] ospf 1

# Create OSPF area 0.

[DeviceA-ospf-1] area 0

# Enable OSPF on interfaces whose primary IP addresses are on network 10.1.1.0/24, 10.5.1.0/24, or 10.6.1.0/24 in area 0.

[DeviceA-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255

[DeviceA-ospf-1-area-0.0.0.0] network 10.5.1.0 0.0.0.255

[DeviceA-ospf-1-area-0.0.0.0] network 10.6.1.0 0.0.0.255

Configuring Device B

# Configure HundredGigE 1/0/1.

<DeviceB> system-view

[DeviceB] interface hundredgige 1/0/1

[DeviceB-HundredGigE1/0/1] ip address 191.3.1.1 255.255.255.0

[DeviceB-HundredGigE1/0/1] quit

# Configure other interfaces in the same way HundredGigE 1/0/1 is configured. (Details not shown.)

# Create service loopback group 1, and specify its service type as Tunnel.

[DeviceB] service-loopback group 1 type tunnel

# Add HundredGigE 1/0/3 to service loopback group 1.

[DeviceB] interface HundredGigE 1/0/3

[DeviceB-HundredGigE1/0/3] port link-mode bridge

[DeviceB-HundredGigE1/0/3] port service-loopback group 1

[DeviceB-HundredGigE1/0/3] quit

# Create a tunnel interface Tunnel 1, and specify the tunnel mode as GRE/IPv4.

[DeviceB] interface tunnel 1 mode gre

# Configure an IP address for the tunnel interface Tunnel 1.

[DeviceB-Tunnel1] ip address 10.5.1.2 24

# Configure the source interface of the tunnel interface Tunnel 1 as HundredGigE 1/0/1.

[DeviceB-Tunnel1] source hundredgige 1/0/1

# Configure the destination address of the tunnel interface Tunnel 1 as the IP address of HundredGigE 1/0/1 on Device A.

[DeviceB-Tunnel1] destination 191.2.1.1

[DeviceB-Tunnel1] quit

# Configure the OSPF router ID as 10.7.1.1.

[DeviceB] router id 10.7.1.1

# Enable OSPF process 1.

[DeviceB] ospf 1

# Create OSPF area 0.

[DeviceB-ospf-1] area 0

# Enable OSPF on interfaces whose primary IP addresses are on network 10.7.1.0/24 or 10.5.1.0/24 in area 0.

[DeviceB-ospf-1-area-0.0.0.0] network 10.7.1.0 0.0.0.255

[DeviceB-ospf-1-area-0.0.0.0] network 10.5.1.0 0.0.0.255

Configuring Device C

# Configure HundredGigE 1/0/1.

<DeviceC> system-view

[DeviceC] interface hundredgige 1/0/1

[DeviceC-HundredGigE1/0/1] ip address 191.4.1.1 255.255.255.0

[DeviceC-HundredGigE1/0/1] quit

# Configure other interfaces in the same way HundredGigE 1/0/1 is configured. (Details not shown.)

# Create service loopback group 1, and specify its service type as Tunnel.

[DeviceC] service-loopback group 1 type tunnel

# Add HundredGigE 1/0/3 to service loopback group 1.

[DeviceC] interface HundredGigE 1/0/3

[DeviceC-HundredGigE1/0/3] port link-mode bridge

[DeviceC-HundredGigE1/0/3] port service-loopback group 1

[DeviceC-HundredGigE1/0/3] quit

# Create a tunnel interface Tunnel 2, and specify the tunnel mode as GRE/IPv4.

[DeviceC] interface tunnel 2 mode gre

# Configure an IP address for the tunnel interface Tunnel 2.

[DeviceC-Tunnel2] ip address 10.6.1.2 24

# Configure the source interface of the tunnel interface Tunnel 2 as HundredGigE 1/0/1.

[DeviceC-Tunnel2] source hundredgige 1/0/1

# Configure the destination address of the tunnel interface Tunnel 2 as the IP address of HundredGigE 1/0/1 on Device A.

[DeviceC-Tunnel2] destination 191.2.1.1

[DeviceC-Tunnel2] quit

# Configure the OSPF router ID as 10.8.1.1.

[DeviceC] router id 10.8.1.1

# Enable OSPF process 1.

[DeviceC] ospf 1

# Create OSPF area 0.

[DeviceC-ospf-1] area 0

# Enable OSPF on interfaces whose primary IP addresses are on network 10.8.1.0/24 or 10.6.1.0/24 in area 0.

[DeviceC-ospf-1-area-0.0.0.0] network 10.8.1.0 0.0.0.255

[DeviceC-ospf-1-area-0.0.0.0] network 10.6.1.0 0.0.0.255

Verifying the configuration

# Verify that Host A can ping Host B successfully.

C:\> ping 10.7.1.2

 

Pinging 10.7.1.2 with 32 bytes of data:

 

Reply from 10.7.1.2: bytes=32 time=19ms TTL=253

Reply from 10.7.1.2: bytes=32 time<1ms TTL=253

Reply from 10.7.1.2: bytes=32 time<1ms TTL=253

Reply from 10.7.1.2: bytes=32 time<1ms TTL=253

 

Ping statistics for 10.7.1.2:

    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 0ms, Maximum = 19ms, Average = 4ms

 

# Verify that Host A can ping Host C successfully.

C:\> ping 10.8.1.2

 

Pinging 10.8.1.2 with 32 bytes of data:

 

Reply from 10.8.1.2: bytes=32 time=18ms TTL=253

Reply from 10.8.1.2: bytes=32 time<1ms TTL=253

Reply from 10.8.1.2: bytes=32 time<1ms TTL=253

Reply from 10.8.1.2: bytes=32 time<1ms TTL=253

 

Ping statistics for 10.8.1.2:

    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 0ms, Maximum = 19ms, Average = 4ms

# Verify that Host B can ping Host C successfully.

C:\> ping 10.8.1.2

 

Pinging 10.8.1.2 with 32 bytes of data:

 

Reply from 10.8.1.2: bytes=32 time=20ms TTL=251

Reply from 10.8.1.2: bytes=32 time<1ms TTL=251

Reply from 10.8.1.2: bytes=32 time<1ms TTL=251

Reply from 10.8.1.2: bytes=32 time<1ms TTL=251

 

Ping statistics for 10.8.1.2:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 0ms, Maximum = 19ms, Average = 4ms

Configuration files

·     Device A

#

 service-loopback group 1 type tunnel

#

interface HundredGigE1/0/1

 ip address 191.2.1.1 255.255.255.0

#

interface HundredGigE1/0/2

 ip address 10.1.1.1 255.255.255.0

#

interface HundredGigE1/0/3

 port link-mode bridge

 port service-loopback group 1

#

interface Tunnel1 mode gre

 source HundredGigE1/0/1

 destination 191.3.1.1

 ip address 10.5.1.1 255.255.255.0

#

interface Tunnel2 mode gre

 source HundredGigE1/0/1

 destination 191.4.1.1

 ip address 10.6.1.1 255.255.255.0

#

router id 10.6.1.1

#

ospf 1

 area 0.0.0.0

  network 10.1.1.0 0.0.0.255

  network 10.5.1.0 0.0.0.255

  network 10.6.1.0 0.0.0.255

#

·     Device B

#

 service-loopback group 1 type tunnel

#

interface HundredGigE1/0/1

 ip address 191.3.1.1 255.255.255.0

#

interface HundredGigE1/0/2

 ip address 10.7.1.1 255.255.255.0

#

interface HundredGigE1/0/3

 port link-mode bridge

 port service-loopback group 1

#

interface Tunnel1 mode gre

 source HundredGigE1/0/1

 destination 191.2.1.1

 ip address 10.5.1.2 255.255.255.0

#

router id 10.7.1.1

#

ospf 1

 area 0.0.0.0

  network 10.7.1.0 0.0.0.255

  network 10.5.1.0 0.0.0.255

#

·     Device C

#

 service-loopback group 1 type tunnel

#

interface HundredGigE1/0/1

 ip address 191.4.1.1 255.255.255.0

#

interface HundredGigE1/0/2

 ip address 10.8.1.1 255.255.255.0

#

interface HundredGigE1/0/3

 port link-mode bridge

 port service-loopback group 1

#

interface Tunnel2 mode gre

 source HundredGigE1/0/1

 destination 191.2.1.1

 ip address 10.6.1.2 255.255.255.0

#

router id 10.8.1.1

#

ospf 1

 area 0.0.0.0

  network 10.8.1.0 0.0.0.255

  network 10.6.1.0 0.0.0.255

#

Related documentation

·     H3C S12500R Switch Router Series Layer 3—IP Routing Command Reference-R3606

·     H3C S12500R Switch Router Series Layer 3—IP Routing Configuration Guide-R3606

·     H3C S12500R Switch Router Series Layer 3—IP Services Command Reference-R3606

·     H3C S12500R Switch Router Series Layer 3—IP Services Configuration Guide-R3606