HP Routing Services -UX 11i v2 Specifying Route Preference, Default Preference Values of Routes

Configuring gated

Specifying Route Preference

Specifying Route Preference

gated maintains a routing table that consists of the route information learned from OSPF and from other active routing protocols, such as RIP or EGP. You can also configure static routes in the /etc/gated.conf file with one or more static clauses (see “Installing Static Routes” on page 90 for more information).

The gated routing pool can therefore contain multiple routes to a single destination. When multiple routes exist, the route chosen by gated is determined by the following (in order of precedence):

•The preference value associated with the route. The preference value is a number in the range from 0 (most preferred) to 255 (least preferred). Routes from different sources have different default preference values. For example, OSPF routes within a given AS have a preference value of 10. Table 3-3 shows the default preference values of various types of routes.

•If multiple routes use the same protocol and have the same preference value, the route with the lowest metric or cost is chosen.

•If metric or cost is the same, the router with the lowest IP address is chosen.

Table 3-3	Default Preference Values of Routes
	Route Type	Preference	/etc/gated.config Configuration
	Interface	0	Can be changed with interface
	routes		statement in Interface class.
	OSPF inter-	10	Cannot be changed.
	and intra-areas
	Internal	20	Generated by BGP or EGP when
	default		routing information is learned from
			a peer.
	ICMP Redirect	30	Can be changed with redirect
			statement in Protocol class.
	SNMP	50	Can be changed in SNMP statement in
			Protocol class.

94 Chapter 3