# Nexthop Groups

Nexthop groups are a way to encapsulate ECMP information together. It's a listing of ECMP nexthops used to forward packets.

nexthop-group NAME

  Create a nexthop-group with an associated NAME. This will put you into a sub-mode where you can specify individual nexthops. To exit this mode type exit or end as per normal conventions for leaving a sub-mode.

backup-group NAME

  Specify a group name containing backup nexthops for this nexthop group.

nexthop [A.B.C.D|X:X::X:X] [INTERFACE [onlink]] [nexthop-vrf NAME] [label LABELS] [vni VNI] [weight WEIGHT] [backup-idx INDEXES]

  Create a v4 or v6 nexthop. All normal rules for creating nexthops that you are used to are allowed here. The syntax was intentionally kept the same as creating nexthops as you would for static routes.

  Parameters:

  - A.B.C.D|X:X::X:X: IPv4 or IPv6 address (optional)

  - INTERFACE: Interface to use (optional)

  - onlink: Treat nexthop as directly attached to the interface (optional)

  - nexthop-vrf NAME: Specify VRF for the nexthop (optional)

  - label LABELS: Specify MPLS label(s) for this nexthop (optional) - Labels must be in the range 16-1048575 - Multiple labels can be specified separated by '/' - Reserved labels (0-15) cannot be used - Maximum of 16 labels allowed

  - vni VNI: Specify VNI for this nexthop (optional) - VNI must be in the range 1-16777215

  - weight WEIGHT: Weight for ECMP load balancing (optional) - Weight must be in the range 1-4294967295

  - backup-idx INDEXES: Specify backup nexthop indexes (optional) - Indexes must be in the range 0-254 - Multiple indexes can be specified separated by ','

resilient buckets (1-256) idle-timer (1-4294967295) unbalanced-timer (1-4294967295)

  Create a resilient Nexthop Group with the specified number of buckets, and associated timers. Instead of using the normal kernel hashing methodology this specifies that X buckets will be created for the nexthop group and when a nexthop is lost the buckets forwarding that particular nexthop will be automatically re-assigned. This cli command must be the first command entered currently. Additionally this command only works with linux 5.19 kernels or newer.

  Parameters:

  - buckets: Number of buckets in the hash (1-256)

  - idle-timer: Idle timer in seconds (1-4294967295)

  - unbalanced-timer: Unbalanced timer in seconds (1-4294967295)