GRE over IPv4 tunnel configuration example
Network requirements
Switch A and Switch B are interconnected through the Internet. Two private IPv4 subnets Group 1 and Group 2 are interconnected through a GRE tunnel between the two switches.
Figure 97: Network diagram
Configuration procedure
Before the configuration, make sure that Switch A and Switch B are reachable to each other.
Configure Switch A:
# Configure an IPv4 address for interface GigabitEthernet 1/0/1.
<SwitchA> system-view [SwitchA] vlan 100 [SwitchA-vlan100] port GigabitEthernet 1/0/1 [SwitchA-vlan100] quit [SwitchA] interface vlan-interface 100 [SwitchA-Vlan-interface100] ip address 10.1.1.1 255.255.255.0 [SwitchA-Vlan-interface100] quit
# Configure an IPv4 address for interface GigabitEthernet 1/0/2, the physical interface of the tunnel.
[SwitchA] vlan 101 [SwitchA-vlan101] port GigabitEthernet 1/0/2 [SwitchA-vlan101] quit [SwitchA] interface vlan-interface 101 [SwitchA-Vlan-interface101] ip address 1.1.1.1 255.255.255.0 [SwitchA-Vlan-interface101] quit
# Create service loopback group 1, and configure the service type as tunnel.
[SwitchA] service-loopback group 1 type tunnel
# Add port GigabitEthernet 1/0/3 to service loopback group 1, and disable STP, NDP, and LLDP on the port.
[SwitchA] interface GigabitEthernet 1/0/3 [SwitchA-GigabitEthernet1/0/3] undo stp enable [SwitchA-GigabitEthernet1/0/3] undo ndp enable [SwitchA-GigabitEthernet1/0/3] undo lldp enable [SwitchA-GigabitEthernet1/0/3] port service-loopback group 1 [SwitchA-GigabitEthernet1/0/3] quit
# Create a tunnel interface Tunnel1.
[SwitchA] interface tunnel 1
# Configure an IPv4 address for the tunnel interface Tunnel1.
[SwitchA-Tunnel1] ip address 10.1.2.1 255.255.255.0
# Configure the tunnel encapsulation mode as GRE over IPv4.
[SwitchA-Tunnel1] tunnel-protocol gre
# Configure the source address of the tunnel interface Tunnel1 as the IP address of the VLAN interface of interface GigabitEthernet 1/0/2.
[SwitchA-Tunnel1] source vlan-interface 101
# Configure the destination address for tunnel interface Tunnel1 (IP address of the VLAN interface to which GigabitEthernet 1/0/2 of Switch B belongs).
[SwitchA-Tunnel1] destination 2.2.2.2
# Apply service loopback group 1 to the tunnel in tunnel interface view.
[SwitchA-Tunnel1] service-loopback-group 1 [SwitchA-Tunnel1] quit
# Configure a static route from Switch A through tunnel interface Tunnel1 to Group 2.
[SwitchA] ip route-static 10.1.3.0 255.255.255.0 tunnel 1
Configure Switch B:
# Configure an IPv4 address for interface GigabitEthernet 1/0/1.
<SwitchB> system-view [SwitchB] vlan 100 [SwitchB-vlan100] port GigabitEthernet 1/0/1 [SwitchB-vlan100] quit [SwitchB] interface vlan-interface 100 [SwitchB-Vlan-interface100] ip address 10.1.3.1 255.255.255.0 [SwitchB-Vlan-interface100] quit
# Configure an IPv4 address for interface GigabitEthernet 1/0/2, the physical interface of the tunnel.
[SwitchB] vlan 101 [SwitchB-vlan101] port GigabitEthernet 1/0/2 [SwitchB-vlan101] quit [SwitchB] interface vlan-interface 101 [SwitchB-Vlan-interface101] ip address 2.2.2.2 255.255.255.0 [SwitchB-Vlan-interface101] quit
# Create service loopback group 1, and configure the service type as tunnel.
[SwitchB] service-loopback group 1 type tunnel
# Add port GigabitEthernet 1/0/3 to service loopback group 1, and disable STP, NDP, and LLDP on the port.
[SwitchB] interface GigabitEthernet 1/0/3 [SwitchB-GigabitEthernet1/0/3] undo stp enable [SwitchB-GigabitEthernet1/0/3] undo ndp enable [SwitchB-GigabitEthernet1/0/3] undo lldp enable [SwitchB-GigabitEthernet1/0/3] port service-loopback group 1 [SwitchB-GigabitEthernet1/0/3] quit
# Create a tunnel interface Tunnel1.
[SwitchB] interface tunnel 1
# Configure an IPv4 address for tunnel interface Tunnel1.
[SwitchB-Tunnel1] ip address 10.1.2.2 255.255.255.0
# Configure the tunnel encapsulation mode as GRE over IPv4.
[SwitchB-Tunnel1] tunnel-protocol gre
# Configure the source address for tunnel interface Tunnel1 (IP address of the VLAN interface to which GigabitEthernet 1/0/2 belongs).
[SwitchB-Tunnel1] source vlan-interface 101
# Configure the destination address for tunnel interface Tunnel1 (IP address of the VLAN interface to which GigabitEthernet 1/0/2 of Switch A belongs).
[SwitchB-Tunnel1] destination 1.1.1.1
# Apply service loopback group 1 to the tunnel in tunnel interface view.
[SwitchB-Tunnel1] service-loopback-group 1 [SwitchB-Tunnel1] quit
# Configure a static route from Switch B through tunnel interface Tunnel1 to Group 1.
[SwitchB] ip route-static 10.1.1.0 255.255.255.0 Tunnel 1
Verify the configuration:
# View the tunnel interface status on Switch A and Switch B.
[SwitchA] display interface tunnel 1 Tunnel1 current state: UP Line protocol current state: UP Description: Tunnel1 Interface The Maximum Transmit Unit is 1476 Internet Address is 10.1.2.1/24 Primary Encapsulation is TUNNEL, service-loopback-group ID is 1. Tunnel source 1.1.1.1, destination 2.2.2.2 Tunnel bandwidth 64 (kbps) Tunnel protocol/transport GRE/IP GRE key disabled Checksumming of GRE packets disabled Last clearing of counters: Never Last 300 seconds input: 0 bytes/sec, 0 packets/sec Last 300 seconds output: 0 bytes/sec, 0 packets/sec 10 packets input, 840 bytes 0 input error 10 packets output, 840 bytes 0 output error [SwitchB] display interface tunnel 1 Tunnel1 current state: UP Line protocol current state: UP Description: Tunnel1 Interface The Maximum Transmit Unit is 1476 Internet Address is 10.1.2.2/24 Primary Encapsulation is TUNNEL, service-loopback-group ID is 1. Tunnel source 2.2.2.2, destination 1.1.1.1 Tunnel bandwidth 64 (kbps) Tunnel protocol/transport GRE/IP GRE key disabled Checksumming of GRE packets disabled Last clearing of counters: Never Last 300 seconds input: 2 bytes/sec, 0 packets/sec Last 300 seconds output: 2 bytes/sec, 0 packets/sec 10 packets input, 840 bytes 0 input error 10 packets output, 840 bytes 0 output error# From Switch B, ping the IP address of VLAN-interface 100 on Switch A.
[SwitchB] ping 10.1.1.1 PING 10.1.1.1: 56 data bytes, press CTRL_C to break Reply from 10.1.1.1: bytes=56 Sequence=1 ttl=255 time=2 ms Reply from 10.1.1.1: bytes=56 Sequence=2 ttl=255 time=2 ms Reply from 10.1.1.1: bytes=56 Sequence=3 ttl=255 time=2 ms Reply from 10.1.1.1: bytes=56 Sequence=4 ttl=255 time=2 ms Reply from 10.1.1.1: bytes=56 Sequence=5 ttl=255 time=2 ms --- 10.1.1.1 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 2/2/2 ms