V Commands
This chapter describes the Cisco NX-OS unicast routing commands that begin with the letter V.
vfhrp delay
To specify the delay period for the initialization of First Hop Redundancy Protocol (FHRP) clients, use the vfhrp delay command.
Command Modesvrf
To create a VPN routing and forwarding instance (VRF) or enter the VRF configuration mode and configure submode commands for the Intermediate System-to-Intermediate System Intradomain Routing Protocol (IS-IS), use the vrf command. To remove a VRF instance or disable the VRF configuration mode, use the no form of this command.
Command ModesAddress-family configuration
Router configuration
VRF configuration
Usage GuidelinesEach VRF mode serves as a separate instance within the IS-IS process. All configuration commands available in the global configuration mode are available in the new VRF mode. For example, each VRF mode must has its own NET configured for that particular instance to be operational. All EXEC commands can be specified to be per-VRF, else with no arguments, it will be applied to the default VRF. Note that interfaces belong to a particular VRF and the appropriate interface will only be applied to the particular interface with the ip/ipv6 router isis command.
The VRF does not become active until you create an identically named VRF in global configuration mode.
When you enter the VRF configuration mode, the following commands are available:
- address-family —Configures an address family. See the address-family (BGP) command for additional information.
- authentication key-chain —Sets the authentication key chain string. See the authentication key-chain command for additional information.
- authentication-check —Checks the authentication. See the authentication-check command for additional information.
- authentication-type — Sets the authentication type. See the authentication-type command for additional information.
- default-information — Controls the origination of a default route. See the default-information originate (IS-IS) command for additional information.
- distance —Configures the administrative distance. See the distance (IS-IS) command for additional information.
- distribute —Distributes routes between ISIS levels. See the distribute command for additional information.
- exit —Exits from the current command mode.
- graceful-restart —Enables the graceful restart for IS-IS process. See the graceful-restart (BGP) command for additional information.
- hostname —Configures the dynamic hostname for IS-IS. See the hostname dynamic command for additional information.
- is-type —Configures the IS type for this IS-IS process. See the is-type command for additional information.
- log-adjacency-changes —Logs the changes in adjacency state. See the log-adjacency-changes (IS-I S ) command for additional information.
- lsp-gen-interval —Configures the LSP generation interval. See the lsp-gen-interval command for additional information.
- lsp-mtu —Sets the LSP MTU. See the lsp-mtu command for additional information.
- max-lsp-lifetime —Sets the maximum LSP lifetime. See the max-lsp-lifetime command for additional information.
- maximum-paths —Sets the maximum paths per destination. See the maximum-paths (IS-IS) command for additional information.
- net —Configures the Network Entity Title for this IS-IS process. See the net command for additional information.
- no —Negates a command or set its defaults.
- redistribute —Redistributes the information from another routing protocol. See the redistribute (IS-IS ) command for additional information.
- reference-bandwidth —Changes the reference bandwidth used for setting interface metric. See the reference-bandwidth command for additional information.
- set-overload-bit —Signals other routers not to use us for transit. See the set-overload-bit command for additional information.
- shutdown —Shuts down this IS-IS process. See the shutdown (IS-IS) command for additional information.
- spf-interval —Configures the SPF interval. See the spf-interval command for additional information.
- summary-address —Configures the IP address summaries. See the summary-address command for additional information.
- wide-metric-only —Advertises only wide metric. See the wide-metric-only command for additional information.
vrf context
To create a virtual routing and forwarding instance (VRF) and enter VRF configuration mode, use the vrf router BGP configuration command. To remove a VRF entry, use the no form of this command.
vrf context { name | management }
Command ModesNeighbor address-family configuration
Router bgp configuration
Usage GuidelinesThe VRF does not become active until you create an identically named VRF in global configuration mode.
When you enter the VRF configuration mode, the following commands are available:
- address-family —Configures an address-family. See the address-family (BGP) command for additional information.
- cluster-id { cluster-id | cluster-ip-addr } —Configures the Route Reflector Cluster-ID (router, vrf). Range: 1 to 4294967295. You can enter the cluster identification as a 32-bit quantity or as an IP address. To remove the cluster ID, use the no form of this command. Together, a route reflector and its clients form a cluster. When a single route reflector is deployed in a cluster, the cluster is identified by the router ID of the route reflector.
The cluster-id command is used to assign a cluster ID to a route reflector when the cluster has one or more route reflectors. Multiple route reflectors are deployed in a cluster to increase redundancy and avoid a single point of failure. When multiple route reflectors are configured in a cluster, the same cluster ID is assigned to all route reflectors. This allows all route reflectors in the cluster to recognize updates from peers in the same cluster and reduces the number of updates that need to be stored in BGP routing tables.
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Note All route reflectors must maintain stable sessions between all peers in the cluster. If stable sessions cannot be maintained, then overlay route reflector clusters should be used instead (route reflectors with different cluster IDs).
- exit —Exits from the current command mode.
- graceful-restart —Configure Graceful Restart functionality. See the graceful-restart (BGP) command for additional information.
- graceful-restart-helper —Configure Graceful Restart Helper mode functionality. See the graceful-restart (BGP) command for additional information.
- log-neighbor-changes —Enables logging of the BGP neighbor resets. To disable the logging of changes in BGP neighbor adjacencies, use the no form of this command. The log-neighbor-changes command enables logging of BGP neighbor status changes (up or down) and resets for troubleshooting network connectivity problems and measuring network stability. Unexpected neighbor resets might indicate high error rates or high packet loss in the network and should be investigated.
Using the log-neighbor-changes command to enable status change message logging does not cause a substantial performance impact, unlike, for example, enabling per BGP update debugging. If the UNIX syslog facility is enabled, messages are sent to the UNIX host running the syslog daemon so that the messages can be stored and archived. If the UNIX syslog facility is not enabled, the status change messages are retained in the internal buffer of the router, and are not stored to disk. You can set the size of this buffer, which is dependent upon the available RAM, using the logging buffered command.
The neighbor status change messages are not tracked if the bgp log-neighbor-changes command is disabled, except for the reset reason, which is always available as output of the show ip bgp neighbors and show bgp ipv6 neighbors commands.
The eigrp log-neighbor-changes command enables logging of Enhanced Interior Gateway Routing Protocol (EIGRP) neighbor adjacencies, but messages for BGP neighbors are logged only if they are specifically enabled with the bgp log-neighbor-changes command.
Use the show logging command to display the log for the BGP neighbor changes.
- neighbor —Configures a BGP neighbor. See the neighbor command for additional information.
- no —Negates a command or set its defaults
- router-id ip-addr —Specifies the IP address to use as the router-id.
- timers bestpath-timeout —Configures the bestpath timeout in seconds. Range: 1 to 3600. Default: 300.
vrf member
To configure object tracking on a virtual routing and forwarding (VRF) instance, use the vrf member command. To remove the object tracking for this route, use the no form of this command.
Command Modes
Usage GuidelinesUse the vrf member command in object tracking configuration mode to track objects in a nondefault VRF.
vrrp
To create a Virtual Router Redundancy Protocol (VRRP) group on a particular Ethernet interface and assign a number to the VRRP group and enter VRRP configuration mode, use the vrrp command. To remove a VRRP group, use the no form of this command.
Command Modes
Usage GuidelinesYou can configure VRRP only if its state is disabled. Make sure that you configure at least one IP address before you attempt to enable a virtual router.
vrrpv3 address-family
To create a Virtual Router Redundancy Protocol version 3 (VRRPv3) group and enter VRRPv3 group configuration mode, use the vrrpv3 address-family command.
Command Modesvrrs leader
To specify a leader’s name to be registered with Virtual Router Redundancy Service (VRRS), use the vrrs leader command.
Command Modesvrrs pathway
To define the Virtual Router Redundancy Service (VRRS) pathway for a VRRS group and enter VRRS pathway configuration mode, use the vrrs pathway command.