G Commands

This chapter describes the Cisco NX-OS unicast routing commands that begin with the letter G.

glbp

To enter GLBP configuration mode and create a Gateway Load Balancing Protocol (GLBP) group, use the glbp command. To delete a GLBP group, use the no form of this command.

glbp group

no glbp group

 
Syntax Description

group

GLBP group number. The range is from 0 to 1023.

 
Defaults

None

 
Command Modes

Interface configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

4.0(1)

This command was introduced.

 
Usage Guidelines

Use the glbp command to enter GLBP configuration mode and create a GLBP group if the group does not exist.

note.gif

Noteblank.gif You must configure all GLBP options before you use the ip command to assign a virtual IP address and activate the GLBP group.

This command does not require a license.

Examples

This example shows how to create GLBP group 10 on Ethernet interface 1/1:

switch(config)# interface ethernet 1/1
switch(config-if)# glbp 10
 

 
Related Commands

Command
Description

ip (GLBP)

Configures a virtual IP address and activates the GLBP group.

show glbp

Displays GLBP information.

glbp timers extended-hold

To enabled extended hold timers for the Gateway Load Balancing Protocol (GLBP), use the glbp timers extended-hold command. To revert to default, use the no form of this command.

glbp timers extended-hold [ timer ]

no glbp timers extended-hold

 
Syntax Description

timer

(Optional) Extended hold time, in seconds. The range is from 10 to 255.

 
Defaults

10 seconds

 
Command Modes

Global configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

5.0(2)

This command was introduced.

 
Usage Guidelines

Use the glbp timers extended-hold command to configure extended Non-stop Forwarding (NSF) support for GLBP.

note.gif

Noteblank.gif You must configure extended hold timers on all GLBP gateways if you configure non-default extended hold timers. You can configure different extended holdtimer values on each GLBP gateway, based on the expected system switchover delays.

This command does not require a license.

Examples

This example shows how to configure the extended hold time for GLBP:

switch(config)# glbp timers extended-hold 30
 

 
Related Commands

Command
Description

ip (GLBP)

Configures a virtual IP address and activates the GLBP group.

show glbp

Displays GLBP information.

graceful-restart (BGP)

To enable the graceful restart and the graceful restart helper capability, use the graceful-restart or the graceful-restart-helper router BGP configuration mode command. To disable graceful restart and the graceful restart helper capability, use the no form of this command.

graceful-restart [ restart-time restart-time | stalepath-time stalepath-time ] graceful-restart-helper

no graceful-restart { restart-time restart-time | stalepath-time stalepath-time } | graceful-restart-helper

 
Syntax Description

restart-time restart-time

(Optional) Sets the maximum time period that the local router will wait for a graceful-restart-capable neighbor to return to normal operation after a restart event occurs. Range: 1 to 3600. Default: 120.

stalepath-time stalepath-time

(Optional) Sets the maximum time period that the local router will hold stale paths for a restarting peer. All stale paths are deleted after this timer expires. The range is from1 to 3600.

graceful-restart-helper

Enables the graceful restart helper capability.

 
Defaults

Graceful restart and graceful restart helper are enabled by default. The following default values are used when the graceful-restart command is entered without any keywords or arguments:

  • restart-time : 120 seconds
  • stalepath-time : 300 seconds
note.gif

Noteblank.gif Changing the restart and stalepath timer values is not required to enable the BGP graceful restart capability. The default values are optimal for most network deployments, and these values should be adjusted only by an experienced network operator.

 
Command Modes

Neighbor address-family configuration
Router bgp configuration
VRF configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

4.0(1)

This command was introduced.

 
Usage Guidelines

The graceful-restart command is used to configure or disable the graceful restart capability on a router in a BGP network.If the graceful restart capability is enabled after a BGP session has been established, you will need to restart the session with a soft or hard reset.

The default timer values for this feature are optimal for most network deployments. We recommend that they are adjusted only by experienced network operators. When adjusting the timer values, the restart timer should not be set to a value greater than the hold time that is carried in the OPEN message. If consecutive restart operations occur, routes (from a restarting router) that were previously marked as stale will be deleted.

The graceful-restart-helper command is used to configure the local BGP router to support the graceful restart of a remote BGP peer.

Examples

This example shows how to enable the BGP graceful restart capability:

switch(config-router)# graceful-restart
switch(config-router)#
 

This example shows how to set the restart timer is set to 240 seconds:

switch(config-router)# graceful-restart restart-timer 240
switch(config-router)#

graceful-restart (EIGRP)

To enable graceful restart for the Enhanced Interior Gateway Routing Protocol (EIGRP), use the graceful-restart command. To reset to default, use the no form of this command.

graceful-restart

no graceful restart

 
Syntax Description

This command has no arguments or keywords.

 
Defaults

Enabled

 
Command Modes

Address-family configuration
Router configuration
Router VRF configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

4.0(3)

This command was introduced.

 
Usage Guidelines

Use the graceful-restart command to allow EIGRP to remain in the data forwarding path through a process restart.

This command requires the Enterprise Services license.

Examples

This example shows how to enable graceful restart:

switch(config)# router eigrp 1
switch(config-router)# graceful-restart

 
Related Commands

Command
Description

timers nsf

Configures timers for nonstop forwarding and graceful restart.

graceful-restart (IS-IS)

To enable the graceful restart for an IS-IS process, use the graceful-restart configuration mode command. To disable graceful restart, use the no form of this command.

graceful-restart

no graceful-restart

 
Syntax Description

This command has no arguments or keywords.

 
Defaults

Graceful restart is enabled by default.

 
Command Modes

Address-family configuration
Router configuration
VRF configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

4.0(1)

This command was introduced.

 
Usage Guidelines

The graceful-restart command is used to configure or disable the graceful restart capability on a router in an IS-IS network. If the graceful restart capability is enabled after an IS-IS session has been established, you will need to restart the session with a soft or hard reset.

This command requires the Enterprise Services license.

Examples

This example shows how to enable the graceful restart capability:

switch(config-router)# graceful-restart
switch(config-router)#

 
Related Commands

Command
Description

feature isis

Enables IS-IS on the router.

router isis

Creates an IS-IS instance.
 

graceful-restart (OSPF)

To configure nonstop forwarding for Open Shortest Path First (OSPF), use the graceful-restart command. To disable this feature, use the no form of this command.

graceful-restart [ grace-period seconds | helper-disable | planned-only ]

no graceful-restart [ grace-period seconds | helper-disable | planned-only ]

 
Syntax Description

grace-period seconds

(Optional) Configures the maximum interval (in seconds) that another router should wait for this router to gracefully restart. The range is from 5 to 1800.

helper-disable

Optional) Disables helper mode. The router will not participate in the graceful restart of a neighbor router.

planned-only

Optional) Enables graceful restart for controlled restarts only.

 
Defaults

Enabled by default. Grace period: 60 seconds

 
Command Modes

Router configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

4.0(1)

This command was introduced.

 
Usage Guidelines

Use the graceful-restart command to allow OSPF to remain in the data forwarding path through a process restart. Set the grace period long enough to allow a typical reboot cycle for Cisco NX-OS. Do not set the grace period too long or your network will be relying on old route information.

This command requires the Enterprise Services license.

Examples

This example shows how to configure a graceful restart to occur only for a planned restart:

switch(config)# router ospf 202
switch(config-router)# graceful-restart grace-period 300 planned-only
 

 
Related Commands

Command
Description

flush-routes

Flushes routes on a nongraceful controlled restart.

graceful-restart (OSPFv3)

To configure nonstop forwarding for Open Shortest Path First version 3 (OSPFv3), use the graceful-restart command. To disable this feature, use the no form of this command.

graceful-restart [ grace-period seconds | helper-disable | planned-only ]

no graceful-restart [ grace-period seconds | helper-disable | planned-only ]

 
Syntax Description

grace-period seconds

(Optional) Configures the maximum interval (in seconds) that another router should wait for this router to gracefully restart. The range is from 5 to 1800.

helper-disable

Optional) Disables helper mode. The router will not participate in the graceful restart of a neighbor router.

planned-only

Optional) Enables graceful restart for controlled restarts only.

 
Defaults

Enabled by default. Grace period: 60 seconds

 
Command Modes

Router configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

4.0(1)

This command was introduced.

 
Usage Guidelines

Use the graceful-restart command to allow OSPFv3 to remain in the data forwarding path through a process restart. Set the grace period long enough to allow a typical reboot cycle for Cisco NX-OS. Do not set the grace period too long or your network will be relying on old route information.

This command requires the Enterprise Services license.

Examples

This example shows how to configure a graceful restart to occur only for a planned restart:

switch(config)# router ospfv3 202
switch(config-router)# graceful-restart grace-period 300 planned-only
 

 
Related Commands

Command
Description

flush-routes

Flushes routes on a nongraceful controlled restart.

graceful-restart t3 manual

To configure the time that Intermediate-System-to-Intermediate System (IS-IS) announces as the adjacency remaining time in its hello message when IS-IS acknowledges a peer restart, use the graceful-restart t3 manual command. To revert to the default setting, use the no form of this command.

graceful-restart t3 manual time

no gracef ul-restart t3 manual

 
Syntax Description

time

Time in seconds. The range is from 30 to 65535.

 
Command Default

60 seconds

 
Command Modes

Router configuration
VRF configuration

 
Supported User Roles

network-admin
vdc-admin

 
Command History

Release
Modification

4.1(2)

This command was introduced.

 
Usage Guidelines

Use the graceful-restart t3 manual command to set the T3 timer, as defined in RFC 3847.

This command requires the Enterprise Services license.

Examples

This example shows how to set the T3 timer:

switch(config-router)# graceful-restart t3 manual 90
switch(config-router)#

 
Related Commands

Command
Description

feature isis

Enables IS-IS on the router.

router isis

Creates an IS-IS instance.