Contents

• Generic Routing Encapsulation Commands

• interface tunnel-ip

• keepalive

• tunnel destination

• tunnel dfbit disable

• tunnel mode

• tunnel source

• tunnel tos

• tunnel ttl

Generic Routing Encapsulation Commands

---

This module describes the commands used to configure generic routing encapsulation (GRE).

For detailed information about GRE concepts, configuration tasks, and examples, refer to the Cisco IOS XR Virtual Private Network Configuration Guide for the Cisco CRS Router.

• interface tunnel-ip
• keepalive
• tunnel destination
• tunnel dfbit disable
• tunnel mode
• tunnel source
• tunnel tos
• tunnel ttl

interface tunnel-ip

To configure a tunnel interface, use the interface tunnel-ip command in the interface global configuration mode. To disable this feature, use the no form of this command.

interface tunnel-ip number

no interface tunnel-ip number

Syntax Description

number

Specifies the instance number of the interface to be configured.

Command Default

None

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the interface tunnel-ip command to enter the interface global configuration mode.

Task ID

Task ID	Operations
interface	read, write

Examples

This example shows how to configure a tunnel interface:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)#

keepalive

To enable keepalive for a tunnel interface, use the keepalive command. To remove keepalive, use the no form of this command.

keepalive [ time_in_seconds [retry_num] ]

no keepalive

Syntax Description

time_in_seconds	Specifies the frequency (in seconds) at which keepalive check is performed. The default is 10 seconds. The minimum value is 1 second.
retry_num	Specifies the number of keepalive retries before declaring that a tunnel destination is unreachable. The default is 3 retries. The minimum value is 1 retry.

Command Default

None

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the keepalive command to enable keepalive for a tunnel interface.

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to configure interface tunnel:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)# keepalive 30

tunnel destination

To specify a tunnel interface's destination, use the tunnel destination command. To remove the destination, use the no form of this command.

Note	The tunnel will not be operational until the tunnel destination is specified.

tunnel destination A.B.C.D

no tunnel destination A.B.C.D

Syntax Description

A.B.C.D

Specifies the IPv4 address of the host destination.

Command Default

None

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to configure interface tunnel:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)# tunnel destination 10.10.10.1

Related Commands

Command	Description
tunnel dfbit disable	Configures the DF bit setting in the tunnel transport header.
tunnel mode	Sets the encapsulation mode of the tunnel interface.
tunnel source	Sets a tunnel interface's source address.
tunnel tos	Specifies the value of the TOS field in the tunnel encapsulating packets.
tunnel ttl	Configures the Time-To-Live (TTL) for packets entering the tunnel.

tunnel dfbit disable

To configure the DF bit setting in the tunnel transport header, use the tunnel dfbit disable command. To revert to the default DF bit setting value, use the no form of this command.

tunnel dfbit disable

no tunnel dfbit disable

Syntax Description

This command has no arguments or keywords.

Command Default

None

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The tunnel dfbit disable command specifies the DF bit setting in the tunnel transport header. The default is to always set the DF bit. Hence, use the tunnel dfbit disable command to override the default.

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to configure interface tunnel:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)# tunnel dfbit disable

Related Commands

Command	Description
tunnel destination	Specifies a tunnel interface's destination.
tunnel mode	Sets the encapsulation mode of the tunnel interface.
tunnel source	Sets a tunnel interface's source address.
tunnel tos	Specifies the value of the TOS field in the tunnel encapsulating packets.
tunnel ttl	Configures the Time-To-Live (TTL) for packets entering the tunnel.

tunnel mode

To set the encapsulation mode of the tunnel interface, use the tunnel mode command. To remove the encapsulation mode, use the no form of this command.

Note	The tunnel will not be operational until the encapsulation mode is specified. Only one mode can be specified for a tunnel instance at any given time.

tunnel mode gre ipv4

no tunnel mode

Syntax Description

This command has no arguments or keywords.

Command Default

Disabled

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to configure interface tunnel:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)#tunnel mode gre ipv4

Related Commands

Command	Description
tunnel dfbit disable	Configures the DF bit setting in the tunnel transport header.
tunnel destination	Specifies a tunnel interface's destination.
tunnel source	Sets a tunnel interface's source address.
tunnel tos	Specifies the value of the TOS field in the tunnel encapsulating packets.
tunnel ttl	Configures the Time-To-Live (TTL) for packets entering the tunnel.

tunnel source

To set a tunnel interface's source address, use the tunnel source command. To remove the source address, use the no form of this command.

Note	The tunnel will not be operational until the tunnel source is specified.

tunnel source { interface_name | A .B .C .D }

no tunnel source { interface_name | A .B .C .D }

Syntax Description

interface_name	Specifies the name of the interface whose IP address will be used as the source address of the tunnel. The interface name can be of a loopback interface or a physical interface.
A.B.C.D	Specifies the IPv4 address to use as the source address for packets in the tunnel.

Command Default

None

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to configure interface tunnel:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)# tunnel source 10.10.10.1

Related Commands

Command	Description
tunnel destination	Specifies a tunnel interface's destination.
tunnel dfbit disable	Configures the DF bit setting in the tunnel transport header.
tunnel mode	Sets the encapsulation mode of the tunnel interface.
tunnel tos	Specifies the value of the TOS field in the tunnel encapsulating packets.
tunnel ttl	Configures the Time-To-Live (TTL) for packets entering the tunnel.

tunnel tos

To specify the value of the TOS field in the tunnel encapsulating packets, use the tunnel tos command. To revert to the default TOS value, use the no form of this command.

tunnel tos tos_value

no tunnel tos tos_value

Syntax Description

tos_value

Specifies the value of the TOS field in the tunnel encapsulating packets. The TOS value ranges between 0 to 255.

Command Default

Copies the TOS/COS bits of the internal IP header to the GRE IP header. In case of labeled payload, EXP bits are copied to TOS bits of the GRE IP header.

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to configure interface tunnel:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)# tunnel tos 100

Related Commands

Command	Description
tunnel destination	Specifies a tunnel interface's destination.
tunnel dfbit disable	Configures the DF bit setting in the tunnel transport header.
tunnel mode	Sets the encapsulation mode of the tunnel interface.
tunnel source	Sets a tunnel interface's source address.
tunnel ttl	Configures the Time-To-Live (TTL) for packets entering the tunnel.

tunnel ttl

To configure the Time-To-Live (TTL) for packets entering the tunnel, use the tunnel ttl command. To revert to the default TTL value, use the no form of this command.

tunnel ttl ttl_value

no tunnel ttl ttl_value

Syntax Description

ttl_value

Specifies the value of TTL for packets entering the tunnel. The TTL value ranges between 1 to 255.

Command Default

The default TTL value is set to 255.

Command Modes

interface configuration

Command History

Release	Modification
Release 3.9.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

This command specifies the Time-To-Live for packets entering the tunnel so that the packets are not dropped inside the carrier network before reaching the tunnel destination.

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to configure interface tunnel:

RP/0/RP0/CPU0:router# configure
RP/0/RP0/CPU0:router(config)# interface tunnel-ip 400
RP/0/RP0/CPU0:router(config-if)#tunnel source 10.10.10.1

Related Commands

Command	Description
tunnel destination	Specifies a tunnel interface's destination.
tunnel dfbit disable	Configures the DF bit setting in the tunnel transport header.
tunnel mode	Sets the encapsulation mode of the tunnel interface.
tunnel tos	Specifies the value of the TOS field in the tunnel encapsulating packets.
tunnel source	Sets a tunnel interface's source address.