STATIC

STATIC is a daemon that handles the installation and deletion of static routes.

Starting STATIC

STATIC supports all the common FRR daemon start options which are documented elsewhere.

Configuration for the daemon should be saved in the FRR integrated configuration file located in /etc/frr/frr.conf, see Integrated Config File for more information on system configuration.

Prior versions of FRR supported reading and writing per-daemon config files; however, with the introduction of the centralized management daemon mgmtd this could no longer be supported.

In order to allow for an orderly transition from per-daemon config files to the integrated config file, FRR daemons will continue to try and read their specific per-daemon configuration file as before. Additionally the config can still be loaded directly using the -f or --config-file CLI options; however, these files will not be updated when the configuration is written (e.g., with the write mem command).

Warning

Per-daemon files will no longer be updated when the user issues a write memory command. Therefore these per-daemon config files should only be used as a mechanism for transitioning to the integrated config, and then removed.

Static Route Commands

Static routing is a very fundamental feature of routing technology. It defines a static prefix and gateway, with several possible forms.

ip route NETWORK GATEWAY [DISTANCE] [table TABLENO] [nexthop-vrf VRFNAME] [vrf VRFNAME]
ip route NETWORK IFNAME [DISTANCE] [table TABLENO] [nexthop-vrf VRFNAME] [vrf VRFNAME]
ip route NETWORK (Null0|blackhole|reject) [DISTANCE] [table TABLENO] [nexthop-vrf VRFNAME] [vrf VRFNAME]
ipv6 route NETWORK [from SRCPREFIX] GATEWAY [DISTANCE] [table TABLENO] [nexthop-vrf VRFNAME] [vrf VRFNAME]
ipv6 route NETWORK [from SRCPREFIX] IFNAME [DISTANCE] [table TABLENO] [nexthop-vrf VRFNAME] [vrf VRFNAME]
ipv6 route NETWORK [from SRCPREFIX] (Null0|blackhole|reject) [DISTANCE] [table TABLENO] [nexthop-vrf VRFNAME] [vrf VRFNAME]

NETWORK is destination prefix with a valid v4 or v6 network based upon initial form of the command.

GATEWAY is the IP address to use as next-hop for the prefix. Currently, it must match the v4 or v6 route type specified at the start of the command.

IFNAME is the name of the interface to use as next-hop. If only IFNAME is specified (without GATEWAY), a connected route will be created.

When both IFNAME and GATEWAY are specified together, it binds the route to the specified interface. In this case, it is also possible to specify onlink to force the kernel to consider the next-hop as “on link” on the given interface.

Alternatively, the gateway can be specified as Null0 or blackhole to create a blackhole route that drops all traffic. It can also be specified as reject to create an unreachable route that rejects traffic with ICMP “Destination Unreachable” messages.

TABLENO is an optional parameter for namespaces that allows you to create the route in a specified table associated with the vrf namespace. table will be rejected if you are not using namespace based vrfs.

vrf VRFNAME allows you to create the route in a specified vrf.

nexthop-vrf VRFNAME allows you to create a leaked route with a nexthop in the specified VRFNAME. nexthop-vrf cannot be currently used with namespace based vrfs.

The IPv6 variant allows the installation of a static source-specific route with the SRCPREFIX sub command. These routes are currently supported on Linux operating systems only, and perform AND matching on packet’s destination and source addresses in the kernel’s forwarding path. Note that destination longest-prefix match is “more important” than source LPM, e.g. 2001:db8:1::/64 from 2001:db8::/48 will win over 2001:db8::/48 from 2001:db8:1::/64 if both match.

Multiple nexthop static route

To create multiple nexthops to the same NETWORK (also known as a multipath route), just reenter the same network statement with different nexthop information.

ip route 10.0.0.1/32 10.0.0.2
ip route 10.0.0.1/32 10.0.0.3
ip route 10.0.0.1/32 eth0

If there is no route to 10.0.0.2 and 10.0.0.3, and interface eth0 is reachable, then the last route is installed into the kernel.

If zebra has been compiled with multipath support, and both 10.0.0.2 and 10.0.0.3 are reachable, zebra will install a multipath route via both nexthops, if the platform supports this.

router> show ip route
S>  10.0.0.1/32 [1/0] via 10.0.0.2 inactive
    via 10.0.0.3 inactive
  *       is directly connected, eth0

ip route 10.0.0.0/8 10.0.0.2
ip route 10.0.0.0/8 10.0.0.3
ip route 10.0.0.0/8 null0 255

This will install a multipath route via the specified next-hops if they are reachable, as well as a high-distance blackhole route, which can be useful to prevent traffic destined for a prefix to match less-specific routes (e.g. default) should the specified gateways not be reachable. E.g.:

router> show ip route 10.0.0.0/8
Routing entry for 10.0.0.0/8
  Known via "static", distance 1, metric 0
    10.0.0.2 inactive
    10.0.0.3 inactive

Routing entry for 10.0.0.0/8
  Known via "static", distance 255, metric 0
    directly connected, Null0

Also, if the user wants to configure a static route for a specific VRF, then a specific VRF configuration mode is available. After entering into that mode with vrf VRF the user can enter the same route command as before, but this time, the route command will apply to the VRF.

# case with VRF
configure
vrf r1-cust1
 ip route 10.0.0.0/24 10.0.0.2
exit-vrf

SR-TE Route Commands

It is possible to specify a route using a SR-TE policy configured in Zebra.

e.g. to use the SR-TE policy with endpoint 6.6.6.6 and color 123 to reach the network 9.9.9.9/24:

ip route 9.9.9.9/24 6.6.6.6 color 123

SRv6 Route Commands

It is possible to specify a static route for ipv6 prefixes using an SRv6 segments instruction. The / separator can be used to specify multiple segments instructions.

ipv6 route X:X::X:X <X:X::X:X|nexthop> segments U:U::U:U/Y:Y::Y:Y/Z:Z::Z:Z

router(config)# ipv6 route 2005::1/64 ens3 segments 2001:db8:aaaa::7/2002::4/2002::3/2002::2

router# show ipv6 route
[..]
S>* 2005::/64 [1/0] is directly connected, ens3, seg6 2001:db8:aaaa::7,2002::4,2002::3,2002::2, weight 1, 00:00:06