set interfaces ethernet <interface> address <address | dhcp | dhcpv6>

Configure interface <interface> with one or more interface addresses.

  • address can be specified multiple times as IPv4 and/or IPv6 address, e.g. and/or 2001:db8::1/64
  • dhcp interface address is received by DHCP from a DHCP server on this segment.
  • dhcpv6 interface address is received by DHCPv6 from a DHCPv6 server on this segment.


set interfaces ethernet eth0 address
set interfaces ethernet eth0 address
set interfaces ethernet eth0 address 2001:db8::ffff/64
set interfaces ethernet eth0 address 2001:db8:100::ffff/64
set interfaces ethernet <interface> ipv6 address autoconf

SLAAC RFC 4862. IPv6 hosts can configure themselves automatically when connected to an IPv6 network using the Neighbor Discovery Protocol via ICMPv6 router discovery messages. When first connected to a network, a host sends a link-local router solicitation multicast request for its configuration parameters; routers respond to such a request with a router advertisement packet that contains Internet Layer configuration parameters.


This method automatically disables IPv6 traffic forwarding on the interface in question.

set interfaces ethernet <interface> ipv6 address eui64 <prefix>

EUI-64 as specified in RFC 4291 allows a host to assign iteslf a unique 64-Bit IPv6 address.

set interfaces ethernet eth0 ipv6 address eui64 2001:db8:beef::/64


set interfaces ethernet <interface> duplex <auto | full | half>

Configure physical interface duplex setting.

  • auto - interface duplex setting is auto-negotiated
  • full - always use full-duplex
  • half - always use half-duplex

VyOS default will be auto.

set interfaces ethernet <interface> speed <auto | 10 | 100 | 1000 | 2500 | 5000 | 10000 | 25000 | 40000 | 50000 | 100000>

Configure physical interface speed setting.

  • auto - interface speed is auto-negotiated
  • 10 - 10 MBit/s
  • 100 - 100 MBit/s
  • 1000 - 1 GBit/s
  • 2500 - 2.5 GBit/s
  • 5000 - 5 GBit/s
  • 10000 - 10 GBit/s
  • 25000 - 25 GBit/s
  • 40000 - 40 GBit/s
  • 50000 - 50 GBit/s
  • 100000 - 100 GBit/s

VyOS default will be auto.

Router Advertisements

Router advertisements are described in RFC 4861#section-4.6.2. They are part of what is known as SLAAC.

set interfaces ethernet <interface> ipv6 router-advert send-advert <true | false>
Enable or disable router advertisements in this <interface>.
set interfaces ethernet <interface> ipv6 router-advert prefix <prefix>
Prefix information is described in RFC 4861#section-4.6.2.


show interfaces ethernet

Show brief interface information.

[email protected]:~$ show interfaces ethernet
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface        IP Address                        S/L  Description
---------        ----------                        ---  -----------
eth0                     u/u  LAN
eth1                     u/u  WAN
eth2             -                                 u/D
show interfaces ethernet <interface>

Show detailed information on given <interface>

[email protected]:~$ show interfaces ethernet eth0
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:50:44:00:f5:c9 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::250:44ff:fe00:f5c9/64 scope link
       valid_lft forever preferred_lft forever

    RX:  bytes    packets     errors    dropped    overrun      mcast
      56735451     179841          0          0          0     142380
    TX:  bytes    packets     errors    dropped    carrier collisions
       5601460      62595          0          0          0          0
show interfaces ethernet <interface> physical

Show information about physical <interface>

[email protected]:~$ show interfaces ethernet eth0 physical
Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   1000baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: No
        Supported FEC modes: Not reported
        Advertised link modes:  Not reported
        Advertised pause frame use: No
        Advertised auto-negotiation: No
        Advertised FEC modes: Not reported
        Speed: 10000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: off
        MDI-X: Unknown
        Supports Wake-on: uag
        Wake-on: d
        Link detected: yes
driver: vmxnet3
bus-info: 0000:0b:00.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: no
show interfaces ethernet <interface> transceiver

Show transceiver information from plugin modules, e.g SFP+, QSFP

[email protected]:~$ show interfaces ethernet eth5 transceiver
   Identifier              : 0x03 (SFP)
   Extended identifier     : 0x04 (GBIC/SFP defined by 2-wire interface ID)
   Connector               : 0x07 (LC)
   Transceiver codes       : 0x00 0x00 0x00 0x01 0x00 0x00 0x00 0x00 0x00
   Transceiver type        : Ethernet: 1000BASE-SX
   Encoding                : 0x01 (8B/10B)
   BR, Nominal             : 1300MBd
   Rate identifier         : 0x00 (unspecified)
   Length (SMF,km)         : 0km
   Length (SMF)            : 0m
   Length (50um)           : 550m
   Length (62.5um)         : 270m
   Length (Copper)         : 0m
   Length (OM3)            : 0m
   Laser wavelength        : 850nm
   Vendor name             : CISCO-FINISAR
   Vendor OUI              : 00:90:65
   Vendor PN               : FTRJ-8519-7D-CS4
   Vendor rev              : A
   Option values           : 0x00 0x1a
   Option                  : RX_LOS implemented
   Option                  : TX_FAULT implemented
   Option                  : TX_DISABLE implemented
   BR margin, max          : 0%
   BR margin, min          : 0%
   Vendor SN               : FNS092xxxxx
   Date code               : 0506xx