System configuration commands

set system ip disable-forwarding

Use this command to disable IPv4 forwarding on all interfaces.

set system ip disable-directed-broadcast

Use this command to disable IPv4 directed broadcast forwarding on all interfaces.

If set, IPv4 directed broadcast forwarding will be completely disabled regardless of whether per-interface directed broadcast forwarding is enabled or not.

set system ip arp table-size <number>

Use this command to define the maximum number of entries to keep in the ARP cache (1024, 2048, 4096, 8192, 16384, 32768).

set system ip multipath layer4-hashing

Use this command to use Layer 4 information for IPv4 ECMP hashing.

Zebra/Kernel route filtering

Zebra supports prefix-lists and Route Maps to match routes received from other FRR components. The permit/deny facilities provided by these commands can be used to filter which routes zebra will install in the kernel.

set system ip protocol <protocol> route-map <route-map>

Apply a route-map filter to routes for the specified protocol. The following protocols can be used: any, babel, bgp, connected, eigrp, isis, kernel, ospf, rip, static, table


If you choose any as the option that will cause all protocols that are sending routes to zebra.

Nexthop Tracking

Nexthop tracking resolve nexthops via the default route by default. This is enabled by default for a traditional profile of FRR which we use. It and can be disabled if you do not want to e.g. allow BGP to peer across the default route.

set system ip nht no-resolve-via-default

Do not allow IPv4 nexthop tracking to resolve via the default route. This parameter is configured per-VRF, so the command is also available in the VRF subnode.

Operational commands

show commands

See below the different parameters available for the IPv4 show command:

vyos@vyos:~$ show ip
Possible completions:
  access-list   Show all IP access-lists
                Show all as-path-access-lists
  bgp           Show Border Gateway Protocol (BGP) information
                Show IP community-lists
                Show extended IP community-lists
  forwarding    Show IP forwarding status
  groups        Show IP multicast group membership
  igmp          Show IGMP (Internet Group Management Protocol) information
                Show IP large-community-lists
  multicast     Show IP multicast
  ospf          Show IPv4 Open Shortest Path First (OSPF) routing information
  pim           Show PIM (Protocol Independent Multicast) information
  ports         Show IP ports in use by various system services
  prefix-list   Show all IP prefix-lists
  protocol      Show IP route-maps per protocol
  rip           Show Routing Information Protocol (RIP) information
  route         Show IP routes

reset commands

And the different IPv4 reset commands available:

vyos@vyos:~$ reset ip
Possible completions:
  arp           Reset Address Resolution Protocol (ARP) cache
  bgp           Clear Border Gateway Protocol (BGP) statistics or status
  igmp          IGMP clear commands
  multicast     IP multicast routing table
  route         Reset IP route