IP-NEXTHOP(8) Linux IP-NEXTHOP(8) # [NAME](#NAME) ip-nexthop - nexthop object management # [SYNOPSIS](#SYNOPSIS) **ip** \[ *ip-OPTIONS* ] **nexthop** { *COMMAND* | **help** } **ip nexthop** { **show** | **flush** } *SELECTOR* **ip nexthop** { **add** | **replace** } id *ID* *NH* **ip nexthop** { **get** | **del** } id *ID* **ip nexthop bucket list BUCKET\_SELECTOR** **ip nexthop bucket get** id *ID* index *INDEX* *SELECTOR* := \[ **id** *ID* ] \[ **dev** *DEV* ] \[ **vrf** *NAME* ] \[ **master** *DEV* ] \[ **groups** ] \[ **fdb** ] *BUCKET\_SELECTOR* := *SELECTOR* | \[ **nhid** *ID* ] *NH* := { **blackhole** | \[ **via** *ADDRESS* ] \[ **dev** *DEV* ] \[ **onlink** ] \[ **encap** *ENCAP* ] \[ **fdb** ] | **group** *GROUP* \[ **hw\_stats** { **on** | **off** } ] \[ **fdb** ] \[ **type** *TYPE* \[ *TYPE\_ARGS* ] ] } *ENCAP* := \[ *ENCAP\_MPLS* ] *ENCAP\_MPLS* := **mpls** \[ *LABEL* ] \[ **ttl** *TTL* ] *GROUP* := **id**\[,**weight**\[/...] *TYPE* := { **mpath** | **resilient** } *TYPE\_ARGS* := \[ *RESILIENT\_ARGS* ] *RESILIENT\_ARGS* := \[ **buckets** *BUCKETS* ] \[ **idle\_timer** *IDLE* ] \[ **unbalanced\_timer** *UNBALANCED* ] # [DESCRIPTION](#DESCRIPTION) **ip nexthop** is used to manipulate entries in the kernel's nexthop tables. [ip nexthop add id ID](#ip) add new nexthop entry [ip nexthop replace id ID](#ip~2) change the configuration of a nexthop or add new one [**via \[ FAMILY \] ADDRESS**](#via) the address of the nexthop router, in the address family FAMILY. Address family must match address family of nexthop instance. [**dev NAME**](#dev) is the output device. [**onlink**](#onlink) pretend that the nexthop is directly attached to this link, even if it does not match any interface prefix. [**encap ENCAPTYPE ENCAPHDR**](#encap) attach tunnel encapsulation attributes to this route. *ENCAPTYPE* is a string specifying the supported encapsulation type. Namely: **mpls** - encapsulation type MPLS *ENCAPHDR* is a set of encapsulation attributes specific to the *ENCAPTYPE.* **mpls** *MPLSLABEL* - mpls label stack with labels separated by */* **ttl** *TTL* - TTL to use for MPLS header or 0 to inherit from IP header [**group GROUP \[ type TYPE \[ TYPE\_ARGS \] \]**](#group) create a nexthop group. Group specification is id with an optional weight (id,weight) and a '/' as a separator between entries. *TYPE* is a string specifying the nexthop group type. Namely: **mpath** - Multipath nexthop group backed by the hash-threshold algorithm. The default when the type is unspecified. **resilient** - Resilient nexthop group. Group is resilient to addition and deletion of nexthops. *TYPE\_ARGS* is a set of attributes specific to the *TYPE.* **resilient** **buckets** *BUCKETS* - Number of nexthop buckets. Cannot be changed for an existing group **idle\_timer** *IDLE* - Time in seconds in which a nexthop bucket does not see traffic and is therefore considered idle. Default is 120 seconds **unbalanced\_timer** *UNBALANCED* - Time in seconds in which a nexthop group is unbalanced and is therefore considered unbalanced. The kernel will try to rebalance unbalanced groups, which might result in some flows being reset. A value of 0 means that no rebalancing will take place. Default is 0 seconds [**blackhole**](#blackhole) create a blackhole nexthop [**fdb**](#fdb) nexthop and nexthop groups for use with layer-2 fdb entries. A fdb nexthop group can only have fdb nexthops. Example: Used to represent a vxlan remote vtep ip. layer-2 vxlan fdb entry pointing to an ecmp nexthop group containing multiple remote vtep ips. [ip nexthop delete id ID](#ip~3) delete nexthop with given id. [ip nexthop show](#ip~4) show the contents of the nexthop table or the nexthops selected by some criteria. [**dev DEV**](#dev~2) show the nexthops using the given device. [**vrf NAME**](#vrf) show the nexthops using devices associated with the vrf name [**master DEV**](#master) show the nexthops using devices enslaved to given master device [**groups**](#groups) show only nexthop groups [**fdb**](#fdb~2) show only fdb nexthops and nexthop groups [ip nexthop flush](#ip~5) flushes nexthops selected by some criteria. Criteria options are the same as show. [ip nexthop get id ID](#ip~6) get a single nexthop by id [ip nexthop bucket show](#ip~7) show the contents of the nexthop bucket table or the nexthop buckets selected by some criteria. [**id ID**](#id) show the nexthop buckets that belong to a nexthop group with a given id [**nhid ID**](#nhid) show the nexthop buckets that hold a nexthop with a given id [**dev DEV**](#dev~3) show the nexthop buckets using the given device [**vrf NAME**](#vrf~2) show the nexthop buckets using devices associated with the vrf name [**master DEV**](#master~2) show the nexthop buckets using devices enslaved to given master device [ip nexthop bucket get id ID index INDEX](#ip~8) get a single nexthop bucket by nexthop group id and bucket index # [EXAMPLES](#EXAMPLES) ip nexthop ls Show all nexthop entries in the kernel. ip nexthop add id 1 via 192.168.1.1 dev eth0 Adds an IPv4 nexthop with id 1 using the gateway 192.168.1.1 out device eth0. ip nexthop add id 2 encap mpls 200/300 via 10.1.1.1 dev eth0 Adds an IPv4 nexthop with mpls encapsulation attributes attached to it. ip nexthop add id 3 group 1/2 Adds a nexthop with id 3. The nexthop is a group using nexthops with ids 1 and 2 at equal weight. ip nexthop add id 4 group 1,5/2,11 Adds a nexthop with id 4. The nexthop is a group using nexthops with ids 1 and 2 with nexthop 1 at weight 5 and nexthop 2 at weight 11. ip nexthop add id 5 via 192.168.1.2 fdb Adds a fdb nexthop with id 5. ip nexthop add id 7 group 5/6 fdb Adds a fdb nexthop group with id 7. A fdb nexthop group can only have fdb nexthops. ip nexthop add id 10 group 1/2 type resilient buckets 32 Add a resilient nexthop group with id 10 and 32 nexthop buckets. # [SEE ALSO](#SEE_ALSO) [**ip**(8)](/man/os/iproute2/ip.8) # [AUTHOR](#AUTHOR) Original Manpage by David Ahern <dsahern@kernel.org> 30 May 2019 iproute2 --- Document: ip-nexthop(8) from iproute2 7.2.0-r1 (Chainguard OS) Source: https://kernel.googlesource.com/pub/scm/network/iproute2/iproute2