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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.
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
number |
Specifies the instance number of the interface to be configured. |
None
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the 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 |
Operations |
---|---|
interface |
read, write |
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)#
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
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. |
None
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the 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 |
Operations |
---|---|
interface |
read, write |
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
To specify a tunnel interface's destination address, use the tunnel destination command. To remove the destination address, use the no form of this command.
Note | The tunnel will not be operational until the tunnel destination is specified. |
tunnel destination ip-address
no tunnel destination ip-address
ip-address |
Specifies the IPv4 address of the host destination. |
None
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
interface |
read, write |
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
Command | Description |
Configures the encapsulation mode of the tunnel interface. | |
Sets a tunnel interface's source address. | |
Specifies the value of the TOS field in the tunnel encapsulating packets. | |
Configures the Time-To-Live (TTL) for packets entering the tunnel. |
To configure the DF bit setting in the tunnel transport header, use the tunnel dfbit command. To revert to the default DF bit setting value, use the no form of this command.
tunnel dfbit disable
no tunnel dfbit
disable |
Disables the DF bit in the outer packet. This allows the outer packet to be fragmented, if required. |
The DF bit value in the outer packet is disabled. This allows outer packet fragmentation, if required.
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
interface |
read, write |
The following example shows how to enable fragmentation over an 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
Command | Description |
Specifies a tunnel interface's destination address. | |
Configures the encapsulation mode of the tunnel interface. | |
Sets a tunnel interface's source address. | |
Specifies the value of the TOS field in the tunnel encapsulating packets. | |
Configures the Time-To-Live (TTL) for packets entering the tunnel. |
To configure the encapsulation mode of the tunnel interface, use the tunnel mode command. To revert the encapsulation to the default IPv4 GRE tunnel mode, use the no form of this command.
tunnel mode gre ipv4}
no tunnel mode
gre |
ipv4 |
Specifies the tunnel as a GRE tunnel over an IPv4 transport network. |
The default tunnel mode is set as a GRE tunnel over an IPv4 transport network.
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
interface |
read, write |
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
Command | Description |
| Specifies a tunnel interface's destination address. |
| Sets a tunnel interface's source address. |
| Specifies the value of the TOS field in the tunnel encapsulating packets. |
| Configures the Time-To-Live (TTL) for packets entering the tunnel. |
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 | ip-address }
no tunnel source { interface_name | ip-address }
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. |
ip-address |
Specifies the IPv4 address to use as the source address for packets in the tunnel. |
None
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
It is recommended that the tunnel source is identified using the interface ID and not the IP address. Using the interface ID enables the router to mark the tunnel as down when the interface is down and the routing protocol tries to find and use an alternate route to the tunnel route.
Task ID |
Operations |
---|---|
interface |
read, write |
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
Command | Description |
| Specifies a tunnel interface's destination address. |
| Configures the encapsulation mode of the tunnel interface. |
| Specifies the value of the TOS field in the tunnel encapsulating packets. |
| Configures the Time-To-Live (TTL) for packets entering the tunnel. |
To specify the value of the TOS field in the tunnel encapsulating packets, use the tunnel tos command. To return to the default TOS value, use the no form of this command.
tunnel tos tos_value
no tunnel tos tos_value
tos_value |
Specifies the value of the TOS field in the tunnel encapsulating packets. The TOS value ranges between 0 to 255. |
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.
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID |
Operations |
---|---|
interface |
read, write |
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
Command | Description |
Specifies a tunnel interface's destination address. | |
Configures the encapsulation mode of the tunnel interface. | |
Sets a tunnel interface's source address. | |
Configures the Time-To-Live (TTL) for packets entering the tunnel. |
To configure the Time-To-Live (TTL) for packets entering the tunnel, use the tunnel ttl command. To undo the configuration, use the no form of this command.
tunnel ttl ttl_value
no tunnel ttl ttl_value
ttl_value |
Specifies the value of TTL for packets entering the tunnel. The TTL value ranges between 1 to 255. |
The default TTL value is set to 255.
interface configuration
Release |
Modification |
---|---|
Release 3.9.0 |
This command was introduced. |
To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the 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 |
Operations |
---|---|
interface |
read, write |
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
Command | Description |
Specifies a tunnel interface's destination address. | |
Configures the encapsulation mode of the tunnel interface. | |
Specifies the value of the TOS field in the tunnel encapsulating packets. | |
Sets a tunnel interface's source address. |