Contents

Configuring tunneling· 1

About tunneling· 1

Restrictions and guidelines: Tunnel interface configuration· 1

Configuring a tunnel interface· 1

About tunnel interface configuration· 1

Tunnel interface configuration tasks at a glance· 1

Creating a tunnel interface· 1

Configuring parameters for tunneled packets· 2

Restoring the default settings of the tunnel interface· 3

Specifying an output interface for tunneled packets· 3

Display and maintenance commands for tunnel interface configuration· 4

Troubleshooting tunnel interface configuration· 4

Tunnel interface not up· 4

 

Configuring tunneling

About tunneling

Tunneling encapsulates the packets of a network protocol within the packets of a second network protocol and transfers them over a virtual point-to-point connection. The virtual connection is called a tunnel. Packets are encapsulated at the tunnel source and de-encapsulated at the tunnel destination.

Restrictions and guidelines: Tunnel interface configuration

Do not specify the same tunnel source and destination addresses for the tunnel interfaces on the same device.

Configuring a tunnel interface

About tunnel interface configuration

Configure a tunnel interface (Layer 3 virtual interface) at both ends of a tunnel. The devices use the tunnel interface to identify, process, and send packets for the tunnel.

Tunnel interface configuration tasks at a glance

To configure a tunnel interface, perform the following tasks:

1.     Creating a tunnel interface

2.     (Optional.) Configuring parameters for tunneled packets

3.     (Optional.) Restoring the default settings of the tunnel interface

4.     (Optional.) Specifying an output interface for tunneled packets

Creating a tunnel interface

1.     Enter system view.

system-view

2.     Create a tunnel interface, specify the tunnel mode, and enter tunnel interface view.

interface tunnel number mode gre [ ipv6 ]

For packet tunneling to succeed, the two ends of a tunnel must use the same tunnel mode.

3.     Configure a source address or source interface for the tunnel interface.

source { ipv4-address | ipv6-address | interface-type interface-number }

By default, no source address or source interface is configured for the tunnel interface.

If you specify a source address, it is used as the source address of tunneled packets.

If you specify a source interface, the primary IP address of this interface is used as the source IP address of tunneled packets.

4.     Configure a destination address for the tunnel interface.

destination { ipv4-address | ipv6-address }

By default, no destination address is configured for the tunnel interface.

The tunnel destination address must be the IP address of the receiving interface on the tunnel peer. It is used as the destination IP address of tunneled packets.

5.     (Optional.) Configure a description for the interface.

description text

By default, the description for a tunnel interface is Tunnel number Interface.

6.     (Optional.) Set the MTU of the tunnel interface.

mtu size

The default settings are as follows:

¡     If the tunnel interface has never been up, the MTU is 64000 bytes.

¡     If the tunnel interface is up, its MTU is identical to the outgoing interface's MTU minus the length of the tunnel headers. The outgoing interface is automatically obtained through routing table lookup based on the tunnel destination address.

7.     (Optional.) Set the expected bandwidth for the tunnel interface.

bandwidth bandwidth-value

The default expected bandwidth (in kbps) is the interface maximum rate divided by 1000.

The expected bandwidth is an informational parameter used only by higher-layer protocols for calculation. You cannot adjust the actual bandwidth of an interface by using this command.

8.     Bring up the tunnel interface.

undo shutdown

By default, a tunnel interface is not administratively down.

Configuring parameters for tunneled packets

1.     Enter system view.

system-view

2.     Enter tunnel interface view.

interface tunnel number

3.     Set the ToS for tunneled packets.

tunnel tos tos-value

By default, the ToS of tunneled packets is the same as that of the original packets.

4.     Set the TTL for tunneled packets.

tunnel ttl ttl-value

The default TTL for tunneled packets is 255.

5.     Set the DF bit for tunneled packets.

tunnel dfbit enable

By default, the DF bit is not set for tunneled packets.

Restoring the default settings of the tunnel interface

Restrictions and guidelines

	CAUTION: This operation might interrupt ongoing network services. Make sure you are fully aware of the impact of this operation when you perform it on a live network.

 

This operation might fail to restore the default settings for some commands for reasons such as command dependencies or system restrictions. Use the display this command in interface view to identify these commands. Use their undo forms or follow the command reference to restore their default settings. If your restoration attempt still fails, follow the error message instructions to resolve the problem.

Procedure

1.     Enter system view.

system-view

2.     Enter tunnel interface view.

interface tunnel number

3.     Restore the default settings of the tunnel interface.

default

Specifying an output interface for tunneled packets

About this task

If ECMP routes exist, the device randomly selects an output interface to forward tunneled packets. To forward tunneled packets over a specific path, perform this task to specify the output interface for the tunneled packets.

Restrictions and guidelines

To ensure successful packet forwarding, the specified output interface must meet the following requirements:

·     The interface is up.

·     The interface has an IP address.

·     The interface has a route to reach the destination.

This feature takes effect only on tunneled packets that are processed by CPU. Whether the CPUs process tunneled packets depends on the device model.

This feature is applicable only to IPv4 ADVPN, IPv6 ADVPN, GRE/IPv4, GRE/IPv6, and VXLAN tunnel interfaces.

Procedure

1.     Enter system view.

system-view

2.     Enter tunnel interface view.

interface tunnel number

3.     Specify an output interface for tunneled packets.

tunnel out-interface interface-type interface-number

By default, no output interface is specified for tunneled packets. If ECMP routes exist, the device randomly selects an output interface to forward tunneled packets.

Display and maintenance commands for tunnel interface configuration

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	IMPORTANT: The WX1800H series, WX2500H series, MAK series, and WX3000H series access controllers do not support parameters or commands that are available only in IRF mode.

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Execute display commands in any view and reset commands in user view.

 

Task	Command	Remarks
Display information about tunnel interfaces.	display interface [ tunnel [ number ] ] [ brief [ description | down ] ]	N/A
Display IPv6 information on tunnel interfaces.	display ipv6 interface [ tunnel [ number ] ] [ brief ]	For more information about this command, see IPv6 basics in Network Connectivity Command Reference.
Clear statistics on tunnel interfaces.	reset counters interface [ tunnel [ number ] ]	N/A
Clear IPv6 statistics on tunnel interfaces.	In standalone mode: reset ipv6 statistics In IRF mode: reset ipv6 statistics [ slot slot-number ]	For more information about this command, see IPv6 basics in Network Connectivity Command Reference.

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Troubleshooting tunnel interface configuration

Tunnel interface not up

Symptom

A tunnel interface configured with related parameters such as tunnel source address, tunnel destination address, and tunnel mode cannot come up.

Analysis

The physical interface of the tunnel does not come up, or the tunnel destination is unreachable.

Solution

1.     To resolve the problem:

¡     Use the display interface or display ipv6 interface command to verify that the physical interface of the tunnel is up. If the physical interface is down, check the network connection.

¡     Use the display ipv6 routing-table or display ip routing-table command to verify that the tunnel destination is reachable. If the route is not available, configure a route to reach the tunnel destination.

2.     If the problem persists, contact H3C Support.