BACK TO BASICS Dynamic routing

Dynamic routing allows routers to adjust, in real time, the paths used for transmitting IP packets. Each protocol involves its own method of defining routes (shortest path, use routes advertised by peers, and so on).

Quagga is a set of daemons cooperating to define the routing tables to be used by the Linux kernel; each routing protocol (most notably BGP, OSPF and RIP) provides its own daemon. The zebra daemon collects information from other daemons and handles static routing tables accordingly. The other daemons are known as bgpd, , ospf6d, ripd, ripngd, isisd, and babeld.

Daemons are enabled by editing the /etc/quagga/daemons file and creating the appropriate configuration file in ; this configuration file must be named after the daemon, with a .conf extension, and belong to the quagga user and the quaggavty group, in order for the /etc/init.d/quagga script to invoke the daemon.

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In addition, the syntax is very close to a standard router’s configuration interface, and network administrators will adapt quickly to quagga.

OSPF is generally the best protocol to use for dynamic routing on private networks, but BGP is more common for Internet-wide routing. RIP is rather ancient, and hardly used anymore.