-h, --help

Print a short description of the daemon's command line options.

-v, --version

Print version and build information for the daemon.

-d, --daemon

The parent process will delay its exit until the daemon/child has finished its initialization and has entered its main loop. This is important for zebra startup because the other daemons will attempt to connect to zebra. A return from zebra -d guarantees its readiness to accept these connections.

-t, --terminal

Opens an interactive VTY session on the terminal, allowing for both state and configuration operations. Note that the terminal starts operating after startup has completed and the configuration file has been loaded.

The process will exit when end of file is detected on the terminal. It is possible to daemonize a process started with -t (but without -d) by sending SIGQUIT to the process (normally mapped to a ^keypress.)

-f, --config_file config-file

Specify a configuration file to be used instead of the default /etc/frr/<daemon>.conf file.

Note that the daemon will attempt to write to this file if the write file command is issued on its VTY interface or through vtysh.

-C, --dryrun

Load the configuration file and check its validity, then exit.

-i, --pid_file pid-file

Output a pid file to a location other than the default /var/run/frr/<daemon>.pid.

-z, --socket zclient-path

Override the path of the ZAPI socket used to communicate between zebra and the various protocol daemons. The default is /var/run/frr/zserv.api. The value of this option must be the same across all daemons.

-N, --pathspace pathspace

Insert pathspace into all default paths, changing the defaults to:

/etc/frr/pathspace/<daemon>.conf /var/run/frr/pathspace/<daemon>.pid /var/run/frr/pathspace/<daemon>.vty /var/run/frr/pathspace/zserv.api

´.´ and ´/´ characters will not be accepted in pathspace, but the empty string will be accepted.

Note that this only changes the respective defaults, it has no effect on the respective path if the -f, -i, -z or --vty_socket options are used.

The purpose of this option is to easily group all file system related bits together for running multiple fully-separate "logical routers" on a system, particularly with Linux network namespaces. Groups of daemons running with distinct pathspace values will be completely unaware of each other and not interact in any way.

This option does not do any system setup (like network namespaces.) This must be done by the user, for example by running:

ip netns exec namespace <daemon> -N namespace

-u, --user user

(default: frr)

-g, --group group

(default: frr)

Change the user/group which the daemon will switch to.

-S, --skip_runas

Skip setting the process effective user and group.

-A, --vty_addr vty-addr

Specify an IP/IPv6 address to bind the TCP VTY interface to. It is generally recommended to specify ::1 or 127.0.0.1. For reasons of backwards compatibility, the default is to listen on all interfaces.

-P, --vty_port vty-port

Override the daemon's default TCP VTY port (each daemon has a different default value upwards of 2600, listed below.) Specifying 0 disables the TCP VTY interface.

Default ports are::

zebra           2601
ripd            2602
ripngd          2603
ospfd           2604
bgpd            2605
ospf6d          2606
isisd           2608
babeld          2609
nhrpd           2610
pimd            2611
ldpd            2612
eigrpd          2613
pbrd            2615
staticd         2616
bfdd            2617
fabricd         2618
vrrpd           2619

Port 2607 is used for ospfd's Opaque LSA API.

--vty_socket vty-path

Overrides the directory used for the <daemon>.vty sockets. vtysh connects to these sockets in order to access each daemon's VTY. Default: /var/run/frr[/<pathspace>]

NB: Unlike the other options, this option specifies a directory, not a full path.

This option is primarily used by the SNAP packaging system, its semantics may change. It should not be necessary in most other scenarios.

-M, --module module[:options]

Load a module named module, optionally passing options to it.

If there is a ´/´ character in module, the value is assumed to be a pathname to a module.

If there is no ´/´ character, the module directory (see next option) is searched first for a module named "<daemon>_<module>.so", then for "<module>.so". This allows for a module to exist in variations appropriate for particular daemons, e.g. zebra_snmp and bgp_snmp, with the correct one selected by -M snmp.

The meaning of options is specific to the module being loaded. Most modules currently ignore it.

Modules are loaded in the order as listed on the command line. This is not generally relevant.

--moduledir module-path

Look for modules in the module-path directory instead of the default /usr/lib/frr/modules. (This path is not affected by the -N option.)

-b, --batch

Runs in batch mode, zebra parses its config and exits.

-s, --nl-bufsize <netlink-buffer-size>

Set netlink receive buffer size. There are cases where zebra daemon can't handle flood of netlink messages from kernel. If you ever see "recvmsg overrun" messages in zebra log, you are in trouble.

Solution is to increase receive buffer of netlink socket. Note that kernel < 2.6.14 doesn't allow increasing it over maximum value defined in /proc/sys/net/core/rmem_max. If you want to do it, you have to increase maximum before starting zebra.

Note that this affects Linux only.

-n, --vrfwnetns

Enable namespace VRF backend. By default, the VRF backend relies on VRF-lite support from the Linux kernel. This option permits discovering Linux named network namespaces and mapping it to FRR VRF contexts.

-r, --retain

When the program terminates, do not flush routes installed by zebra from the kernel.