ip-nexthop(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | SEE ALSO | AUTHOR | COLOPHON

IP-NEXTHOP(8)                     Linux                    IP-NEXTHOP(8)

NAME         top

       ip-nexthop - nexthop object management

SYNOPSIS         top

       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 [ 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         top

       ip nexthop is used to manipulate entries in the kernel's nexthop
       tables.

       ip nexthop add id ID
              add new nexthop entry

       ip nexthop replace id ID
              change the configuration of a nexthop or add new one

              via [ FAMILY ] ADDRESS
                     the address of the nexthop router, in the address
                     family FAMILY.  Address family must match address
                     family of nexthop instance.

              dev NAME
                     is the output device.

              onlink pretend that the nexthop is directly attached to
                     this link, even if it does not match any interface
                     prefix.

              encap ENCAPTYPE ENCAPHDR
                     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 ] ]
                     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
                     create a blackhole nexthop

              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
              delete nexthop with given id.

       ip nexthop show
              show the contents of the nexthop table or the nexthops
              selected by some criteria.

              dev DEV
                     show the nexthops using the given device.

              vrf NAME
                     show the nexthops using devices associated with the
                     vrf name

              master DEV
                     show the nexthops using devices enslaved to given
                     master device

              groups show only nexthop groups

              fdb    show only fdb nexthops and nexthop groups

       ip nexthop flush
              flushes nexthops selected by some criteria. Criteria
              options are the same as show.

       ip nexthop get id ID
              get a single nexthop by id

       ip nexthop bucket show
              show the contents of the nexthop bucket table or the
              nexthop buckets selected by some criteria.

              id ID
                     show the nexthop buckets that belong to a nexthop
                     group with a given id

              nhid ID
                     show the nexthop buckets that hold a nexthop with a
                     given id

              dev DEV
                     show the nexthop buckets using the given device

              vrf NAME
                     show the nexthop buckets using devices associated
                     with the vrf name

              master DEV
                     show the nexthop buckets using devices enslaved to
                     given master device

       ip nexthop bucket get id ID index INDEX
              get a single nexthop bucket by nexthop group id and bucket
              index

EXAMPLES         top

       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         top

       ip(8)

AUTHOR         top

       Original Manpage by David Ahern <dsahern@kernel.org>

COLOPHON         top

       This page is part of the iproute2 (utilities for controlling
       TCP/IP networking and traffic) project.  Information about the
       project can be found at 
       ⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩.
       If you have a bug report for this manual page, send it to
       netdev@vger.kernel.org, shemminger@osdl.org.  This page was
       obtained from the project's upstream Git repository
       ⟨https://git.kernel.org/pub/scm/network/iproute2/iproute2.git⟩ on
       2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-18.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

iproute2                       30 May 2019                 IP-NEXTHOP(8)