# Router Nexthop

The `nv unset` commands remove the configuration you set with the equivalent `nv set` commands. This guide only describes an `nv unset` command if it differs from the `nv set` command.

## nv set router nexthop group <nexthop-group-id> via <via-id>

Configures the next hop router for the next hop group.

### Command Syntax

Syntax | Description
--- | ---
`<nexthop-group-id>` | The next hop group ID.
`<via-id>` | The IP address of the nexthop router.

### Version History

Introduced in Cumulus Linux 5.4.0

### Example

    cumulus@switch:~$ nv set router nexthop group 10 via 10.0.1.0

## nv set router nexthop group <nexthop-group-id> via <via-id> interface <interface-name>

Configures the next hop router and interface for the next hop group.

### Command Syntax

Syntax | Description
--- | ---
`<nexthop-group-id>` | The next hop group ID.
`<via-id>` | The IP address of the nexthop router.
`<interface-name>` | The interface name.

### Version History

Introduced in Cumulus Linux 5.4.0

### Example

    cumulus@switch:~$ nv set router nexthop group 10 via 10.10.10.101 interface swp51

## nv set router nexthop group <nexthop-group-id> via <via-id> vrf <vrf-name>

Configures the next hop router and VRF for the next hop group.

### Command Syntax

Syntax | Description
--- | ---
`<nexthop-group-id>` | The next hop group ID.
`<via-id>` | The IP address of the nexthop router.
`<vrf-name>` | The VRF name.

### Version History

Introduced in Cumulus Linux 5.4.0

### Example

    cumulus@switch:~$ nv set router nexthop group 10 via 10.10.10.101 vrf default

## nv set vrf <vrf-id> router nexthop-tracking <afi>

Configures next hop tracking for the specified address family. Next hop tracking reduces the BGP convergence time by monitoring next hop address changes in the routing table.

### Command Syntax

Syntax | Description
--- | ---
`<vrf-name>` | The VRF name.
`<afi>` | The address family: IPv4 or IPv6.

### Version History

Introduced in Cumulus Linux 5.4.0

### Example

    cumulus@switch:~$ nv set vrf default router nexthop-tracking ipv4

## nv set vrf <vrf-id> router nexthop-tracking <afi> resolved-via-default

Enables and disables nexthop tracking resolved via default.

In Cumulus Linux 5.14 and earlier, you specify `on` or `off`.

### Command Syntax

Syntax | Description
--- | ---
`<vrf-name>` | The VRF name.
`<afi>` | The address family: IPv4 or IPv6.

### Version History

Introduced in Cumulus Linux 5.4.0

### Example

    cumulus@switch:~$ nv set vrf default router nexthop-tracking ipv4 resolved-via-default enabled

## nv set vrf <vrf-id> router nexthop-tracking <afi> route-map <nht-routemap-id>

Applies the specified nexthop tracking route map.

### Command Syntax

Syntax | Description
--- | ---
`<vrf-name>` | The VRF name.
`<afi>` | The address family: IPv4 or IPv6.
`<nht-routemap-id>` | The next hop tracking route map name.

### Version History

Introduced in Cumulus Linux 5.4.0

### Example

    cumulus@switch:~$ nv set vrf default router nexthop-tracking ipv4 route-map ROUTEMAP1

## nv set vrf <vrf-id> router nexthop-tracking <afi> route-map <nht-routemap-id> protocol <protocol-id>

Applies the specified nexthop tracking route map for the specified protocol. You can specify `bgp`, `ospf`, `ospf6`, or `static`.

### Command Syntax

Syntax | Description
--- | ---
`<vrf-name>` | The VRF name.
`<afi>` | The address family: IPv4 or IPv6.
`<nht-routemap-id>` | The next hop tracking route map name.
`<protocol-id>` | The protocol: `bgp`, `ospf`, `ospf6`, or `static`.

### Version History

Introduced in Cumulus Linux 5.4.0

### Example

    cumulus@switch:~$ nv set vrf default router nexthop-tracking ipv4 route-map ROUTEMAP1 bgp