Table Of Contents
dead-interval (OSPF virtual link)
dead-interval (OSPFv3 virtual link)
default-information originate (IS-IS)
default-information originate (EIGRP)
default-information originate (OSPF)
default-information originate (OSPFv3)
default-information originate (RIP)
D Commands
This chapter describes the Cisco NX-OS unicast routing commands that begin with the letter D.
dead-interval (OSPF virtual link)
To set the interval during which at least one hello packet must be received from a neighbor on an Open Shortest Path First (OSPF) virtual link before the router declares that neighbor as down, use the dead interval command. To restore the default, use the no form of this command.
dead-interval seconds
no dead-interval
Syntax Description
Defaults
The default value for seconds is our times the interval set by the hello-interval command.
Command Modes
Virtual link configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
Use the dead interval command in virtual link configuration mode to configure the dead interval advertised in OSPF hello packets. This value must be the same for all networking devices on the virtual link.
You can configure a shorter dead interval (seconds) to detect a down neighbor faster and improve convergence. A shorter dead interval may lead to virtual link instability by incorrectly declaring a slow neighbor as down.
Use the show ip ospf virtual-links command to verify the dead interval.
This command requires the Enterprise Services license.
Examples
The following example shows how to configure the OSPF dead interval to 20 seconds:
switch(config)# ospf 201switch(config-router)# area 99 virtual-link 192.0.2.4switch(config-router-vlink)# dead-interval 20Related Commands
dead-interval (OSPFv3 virtual link)
To set the interval during which at least one hello packet must be received from a neighbor on an Open Shortest Path First version 3 (OSPFv3) virtual link before the router declares that neighbor as down, use the dead interval command. To restore the default, use the no form of this command.
dead-interval seconds
no dead-interval
Syntax Description
Defaults
The default value for seconds is our times the interval set by the hello-interval command.
Command Modes
Virtual link configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
Use the dead interval command in virtual link configuration mode to configure the dead interval advertised in OSPFv3 hello packets. This value must be the same for all networking devices on the virtual link.
You can configure a shorter dead interval (seconds) to detect a down neighbor faster and improve convergence. A shorter dead interval may lead to virtual link instability by incorrectly declaring a slow neighbor as down.
Use the show ospfv3 virtual-links command to verify the dead interval.
This command requires the Enterprise Services license.
Examples
This example shows how to configure the OSPFv3 dead interval to 20 seconds:
switch(config)# ospfv3 201switch(config-router)# area 99 virtual-link 192.0.2.4switch(config-router-vlink)# dead-interval 20Related Commands
default-information originate (IS-IS)
To control the origination of a default route, use the default-information originate command.
default-information originate [always] [route-map name]
Syntax Description
always
Always advertise the default route.
route-map name
Specifies the name of the routing rules route map to announce default routes. The name can be up to 63 characters.
Command Default
The default route is not redistributed into the IS-IS routing domain.
Command Modes
Router configuration
VRF configurationSupported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
You can force a default route into an IS-IS routing domain. Whenever you specifically configure redistribution of routes into an IS-IS routing domain, by default, the default route is not redistributed into the IS-IS routing domain. The default-information originate route-map command generates a default route into IS-IS, which can be controlled by a route map. You can use the route map to identify the level into which the default route is to be announced, and you can specify other filtering options configurable under a route map. You can use a route map to conditionally advertise the default route, depending on the existence of another route in the routing table of the router.
Examples
The following example shows how to always advertise the default route:
switch(config)# router isis TEST1switch(config-router)# default-information originate alwaysswitch(config-router)#The following example shows how to specify a route map to conditionally advertise the default route:
switch(config)# router isis TEST1switch(config-router)# default-information originate route-map CORE1switch(config-router)#Related Commands
exit
Exits the current configuration mode.
feature isis
Enables IS-IS on the router.
no
Negates a command or sets its defaults.
router isis
Enables IS-IS.
default-information originate (EIGRP)
To generate a default route into the Enhanced Interior Gateway Routing Protocol (EIGRP), use the default-information originate command in the appropriate configuration mode. To disable this feature, use the no form of this command.
default-information originate [always] [route-map map-name]
no default-information originate
Syntax Description
Defaults
Disabled
Command Modes
Address-family configuration
Router configuration
Router VRF configurationSupported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
This command requires the Enterprise Services license.
Examples
The following example shows how to originate a default route (0.0.0.0/0) to all routes that pass the Condition route map.
switch(config)# router eigrp 201switch(config-router)# address-family ipv4 unicastswitch(config-router-af)# default-information originate route-map ConditionRelated Commands
default-information originate (OSPF)
To generate a default external route into an Open Shortest Path First (OSPF) routing domain, use the default-information originate command. To disable this feature, use the no form of this command.
default-information originate [always] [route-map map-name]
no default-information originate [always] [route-map map-name]
Syntax Description
Defaults
Advertises the default route if the route is in the route table.
Command Modes
Router configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
Use the default-information originate command to assign a default route for redistributed routes. Whenever you use the redistribute command to redistribute routes into an OSPF routing domain, Cisco NX-OS automatically becomes an Autonomous System Boundary Router (ASBR). However, an ASBR does not, by default, generate a default route into the OSPF routing domain.
Use the route-map keyword to filter redistributed routes so that Cisco NX-OS generates a default route only for routes that pass the route map. Use the always keyword to generate the default route regardless of whether the default route is in the route table.
This command requires the Enterprise Services license.
Examples
The following example shows how to configure the default route redistributed into the OSPF routing domain for the Enhanced Interior Gateway Protocol (EIGRP):
switch(config)# router ospf 109switch(config-router)# redistribute eigrp 108 route-map EigrpPolicyswitch(config-router)# default-information originate alwaysRelated Commands
redistribute (OSPF)
Redistributes routes from one routing domain into OSPF.
route-map
Defines a filter policy for routes.
default-information originate (OSPFv3)
To generate a default external route into an Open Shortest Path First version 3 (OSPFv3) routing domain, use the default-information originate command. To disable this feature, use the no form of this command.
default-information originate [always] [route-map map-name]
no default-information originate [always] [route-map map-name]
Syntax Description
Defaults
Advertises the default route if the route is in the route table.
Command Modes
Address-family configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
Use the default-information originate command to assign a default route for redistributed routes. Whenever you use the redistribute command to redistribute routes into an OSPFv3 routing domain, Cisco NX-OS automatically becomes an Autonomous System Boundary Router (ASBR). However, an ASBR does not, by default, generate a default route into the OSPFv3 routing domain.
Use the route-map keyword to filter redistributed routes so that Cisco NX-OS generates a default route only for routes that pass the route map. Use the always keyword to generate the default route regardless of whether the default route is in the route table.
This command requires the Enterprise Services license.
Examples
This example shows how to configure the default route redistributed into the OSPFv3 routing domain for the Border Gateway Protocol (BGP):
switch(config)# router ospfv3 109switch(config-router)# redistribute bgp 108 route-map bgpPolicyswitch(config-router)# address-family ipv6 unicastswitch(config-router-af)# default-information originate alwaysRelated Commands
redistribute (OSPFv3)
Redistributes routes from one routing domain into OSPFv3.
route-map
Defines a filter policy for routes.
default-information originate (RIP)
To generate a default route into the the Routing Information Protocol (RIP), use the default-information originate command in router address-family configuration mode. To disable this feature, use the no form of this command.
default-information originate [always] [route-map map-name]
no default-information originate
Syntax Description
Defaults
This command is disabled by default.
Command Modes
Router address-family configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
This command does not require a license.
Examples
The following example shows how to originate a default route (0.0.0.0/0) to all routes that pass the Condition route map.
switch(config)# router rip Enterpriseswitch(config-router)# address-family ipv4 unicastswitch(config-router-af)# default-information originate route-map ConditionRelated Commands
default-metric (EIGRP)
To set metrics for an Enhanced Interior Gateway Routing Protocol (EIGRP), use the default-metric command. To remove the metric value and restore the default state, use the no form of this command.
default-metric bandwidth delay reliability loading mtu
no default-metric
Syntax Description
Defaults
bandwidth: 100000
delay: 100 (tens of microseconds)
reliability: 255
loading: 1
MTU: 1500Command Modes
Address-family configuration
Router configuration
Router VRF configurationSupported User Rolesnetwork-admin
vdc-adminCommand History
4.0(1)
This command was introduced.
4.0(3)
Changed the default value for MTU to 1492.
Usage Guidelines
Use the default-metric command with the redistribute command to use the same metric value for all redistributed routes. A default metric helps solve the problem of redistributing routes with incompatible metrics. Whenever external metrics do not convert to EIGRP metrics, you can use a default metric to provide a reasonable substitute to the external metric and enable the redistribution to proceed.
This command requires the Enterprise Services license.
Examples
The following example shows how to take redistributed Routing Information Protocol (RIP) metrics and translate them into EIGRP metrics with the following values: bandwidth = 1000, delay = 100, reliability = 250, loading = 100, and MTU = 1500.
switch(config)# router eigrp 1switch(config-router)# address-family ipv4 unicastswitch(config-router-af)# redistribute rip 100 route-map filterRIPswitch(config-router-af)# default-metric 1000 100 250 100 1500Related Commands
redistribute
Redistributes routes from one routing domain into another routing domain.
default-metric (OSPF)
To set default metric values for the Open Shortest Path First (OSPF) routing protocol, use the default-metric command. To return to the default state, use the no form of this command.
default-metric metric-value
no default-metric metric-value
Syntax Description
metric-value
Default metric value appropriate for the specified routing protocol. The range is from 1 to 1677214.
Defaults
The metric for redistributed, connected, and static routes is set to 0.
Command Modes
Router configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
Use the default-metric command with the redistribute command to configure the same metric value for all redistributed routes. A default metric helps to redistribute routes with incompatible metrics. Whenever external route metrics do not convert to an OSPF metric, use a default metric to enable the redistribution to proceed.
This command requires the Enterprise Services license.
Examples
The following example shows how to configure OSPF to redistribute RIP and BGP and set the default metric to 10:
switch(config)# router ospf 201switch(config-router)# default-metric 10switch(config-router)# redistribute rip 109 route-map FilterRipswitch(config-router)# redistribute bgp 4 route-map FilterBgpRelated Commands
default-metric (OSPFv3)
To set default metric values for the Open Shortest Path First version 3 (OSPFv3) routing protocol, use the default-metric command. To return to the default state, use the no form of this command.
default-metric metric-value
no default-metric metric-value
Syntax Description
metric-value
Default metric value appropriate for the specified routing protocol. The range is from 1 to 1677214.
Defaults
The metric for redistributed, connected, and static routes is set to 0.
Command Modes
Address-family configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
Use the default-metric command with the redistribute command to configure the same metric value for all redistributed routes. A default metric helps to redistribute routes with incompatible metrics. Whenever external route metrics do not convert to an OSPFv3 metric, use a default metric to enable the redistribution to proceed.
This command requires the Enterprise Services license.
Examples
This example shows how to configure OSPFv3 to redistribute RIP and BGP and set the default metric to 10:
switch(config)# router ospfv3 201switch(config-router)# address-family ipv6 unicastswitch(config-router-af)# default-metric 10switch(config-router-af)# exitswitch(config-router)# redistribute rip 109 route-map FilterRipswitch(config-router)# redistribute bgp 4 route-map FilterBgpRelated Commands
redistribute (OSPFv3)
Redistributes routes from another routing domain into OSPFv3.
default-metric (RIP)
To set default metric values for the the Routing Information Protocol (RIP), use the default-metric command in router address-family configuration mode. To return to the default state, use the no form of this command.
default-metric value
no default-metric [value]
Syntax Description
Defaults
value: 1
Command Modes
Router address-family configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
Use the default-metric command with the redistribute command to use the same metric value for all redistributed routes. A default metric helps solve the problem of redistributing routes with incompatible metrics. Whenever external metrics do not convert to RIP metrics, you can use a default metric to provide a reasonable substitute to the external metric and enable the redistribution to proceed.
This command does not require a license.
Examples
The following example shows how to advertise Open Shortest Path First (OSPF) routes using RIP and assign the OSPF-derived routes with a RIP metric of 10:
switch(config)# router rip Enterpriseswitch(config-router)# address-family ipv4 unicastswitch(config-router-af)# default-metric 10switch(config-router-af)# redistribute ospf 109 route-map filterTestRelated Commands
delay (HSRP)
To delay HSRP initialization after a reload or after an interface comes up, use the forwarder preempt command. To disable this function, use the no form of this command.
delay minimum [min-delay] reload [reload-delay]
no delay minimum [min-delay] reload [reload-delay]
Syntax Description
Command Default
The HSRP delay default is 0 seconds.
Command Modes
Interface mode
Supported User RolesSuperuser
VDC administratorCommand History
Usage Guidelines
Use delay hsrp command to delay HSRP initialization either after a reload or after an interface comes up. This configuration allows the interface and router to stabilize after the interface comes up and helps prevent HSRP state flapping.
This command does not require a license.
Examples
This example shows how to configure a minimum delay of 3 seconds, and a group initialization delay of 10 seconds:
switch(config)# configure terminalswitch(config)# interface ethernet 0switch(config)# ip address 172.16.6.5 255.255.255.0switch(config)# hsrp 1switch(config)# delay minimum 3 reload 10switch(config)# ip 172.16.6.100Related Commands
distance (IS-IS)
To define an administrative distance for routes that are inserted into the routing table, use the distance configuration mode command. To return the administrative distance to its default distance definition, use the no form of this command.
distance value
no distance
Syntax Description
Command Default
The default route is not redistributed into the IS-IS routing domain.
Command Modes
Router configuration
VRF configurationSupported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer from 0 to 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.
This command requires the Enterprise Services license.
Examples
The following example shows how to set the administrative distance to 90:.
switch(config)# router isis TEST1switch(config-router)# distance 90Related Commands
feature isis
Enables IS-IS on the router.
net
Specifies the Network Entity Title (NET) for an IS-IS process.
router isis
Enables IS-IS.
distance (EIGRP)
To allow the use of two administrative distances—internal and external—for the Enhanced Interior Gateway Routing Protocol (EIGRP) that could provide a better route to a node, use the distance command. To reset to default, use the no form of this command.
distance internal-distance external-distance
no distance
Syntax Description
Defaults
internal-distance: 90
external-distance: 170Command Modes
Address-family configuration
Router configuration
Router VRF configurationSupported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer from 0 to 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means that the routing information source cannot be trusted and should be ignored.
Use the distance command if another protocol is known to provide a better route to a node than was actually learned through the external EIGRP or some internal routes should be preferred by EIGRP.
This command requires the Enterprise Services license.
Examples
The following example shows how to set the administrative distance of all EIGRP 1 internal routes to 80 and all EIGRP external routes to 130:
switch(config)# router eigrp 1switch(config-router)# distance 80 130Related Commands
show ip eigrp
Displays information about the Enhanced Interior Gateway Routing Protocol (EIGRP) running on the router.
distance (OSPF)
To define the Open Shortest Path First (OSPF) route administrative distance, use the distance command. To restore the default, use the no form of this command.
distance distance
no distance
Syntax Description
distance
Administrative distance for all routes local to this OSPF process. The range is from 1 to 255.
Defaults
110
Command Modes
Router configuration
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Use the distance command to set a distance for an entire group of routes. Use the distance command when you configure multiple routing protocols, and you want to choose one set of routes over the other.
This command requires the Enterprise Services license.
Examples
The following example shows how to set the distance to 200, making the route less reliable:
switch(config)# router ospf 1switch(config-router)# distance 200switch(config-router)# router ospf 2switch(config-router)# distance 20distance (OSPFv3)
To define the Open Shortest Path First version 3 (osPFv3) route administrative distance, use the distance command. To restore the default, use the no form of this command.
distance distance
no distance
Syntax Description
distance
Administrative distance for all routes local to this OSPFv3 process. The range is from 1 to 255.
Defaults
110
Command Modes
Address-family configuration
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Use the distance command to set a distance for an entire group of routes. Use the distance command when you configure multiple routing protocols, and you want to choose one set of routes over the other.
This command requires the Enterprise Services license.
Examples
This example shows how to set the distance to 200, making the route less reliable:
switch(config)# router ospfv3 1switch(config-router)# address-family ipv6 unicastswitch(config-router-af)# distance 200distance (RIP)
To define the administrative distance assigned to routes discovered by the the Routing Information Protocol (RIP), use the distance command in the router address-family configuration mode. To remove the distance and restore the system to its default condition, use the no form of this command.
distance admin-distance
no distance admin-distance
Syntax Description
Defaults
admin-distance: 120
Command Modes
Router address-family configuration
Command History
Usage Guidelines
Use the distance command to change the preference of RIP routes over other protocol routes. Numerically, an administrative distance is an integer from 0 to 255. In general, a higher value indicates a lower trust rating. An administrative distance of 255 means that the routing information source cannot be trusted at all and should be ignored.
Table 1-1 lists default administrative distances.
This command does not require a license.
Examples
The following example shows how to set the administrative distance for RIP:
switch(config)# router rip Enterpriseswitch(config-router)# address-family ipv4 unicastswitch(config-router-af)# distance 85Related Commands
address-family
Enters address-family configuration mode.
redistribute
Redistributes routes from one routing domain into RIP.
distribute
To distribute routes between specific IS-IS levels, use the distribute command. To return to the default setting, use the no form of this command.
distribute {level-1 | level-2} into {level-1 | level-2} {all | route-map name}
Syntax Description
Command Default
The default route is not distributed into the IS-S routing domain. If enabled, IS-IS allows distribution of route between level-1 and level-2 such that optimal inter-area routing could be obtained.
This command requires the Enterprise Services license.
Command Modes
Router configuration
VRF configurationSupported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
level-1—Summarizes the IP address into the level-1 area. Only routes redistributed into Level 1 are summarized with the configured address and mask value.
level-2—Summarizes the IP address into the level-2 area. Routes learned by level-1 routing are summarized into the level-2 backbone with the configured address and mask value. Redistributed routes into level-2 IS-IS will be summarized also.
In IS-IS, all areas are stub areas, which means that no routing information is leaked from the backbone (level-2) into areas (level-1). Level-1-only routers use default routing to the closest level-1-level-2 router in their area. This command enables you to redistribute level-2 IP routes into level-1 areas. This redistribution enables level-1-only routers to pick the best path for an IP prefix to get out of the area. This is an IP-only feature, CLNS routing is still stub routing.
For more control and scalability, a distribute list or a route map can control which level-2 IP routes can be redistributed into level-1. This command allows large IS-IS-IP networks to use areas for better scalability.
Examples
This example distributes level-1 routes into a level-2 network:
switch(config)# distribute level-1 into level-2