HP-UX Reference (11i v3 07/02) - 4 File Formats (vol 8)

g
gated.conf(4) gated.conf(4)
Route Filters
All the formats allow route filters as shown below. See the section on route filters for a detailed explanation
of how they work. When no route filtering is specified (when restrict is specified on the first line of a
statement), all routes from the specified source will match that statement. If any filters are specified, only
routes that match the specified filters will be imported. Put differently, if any filters are specified, an all
restrict; is assumed at the end of the list.
network [ exact | refines ]
network mask mask [exact | refines ]
network masklen number [ exact | refines ]
default
host host
Importing routes from BGP and EGP
import proto bgp | egp autonomoussystem autonomous_system
restrict ;
import proto bgp | egp autonomoussystem autonomous_system
[ preference preference ] {
route_filter [ restrict |(preference preference )];
};
import proto bgp aspath aspath_regexp
origin any |([igp ][egp ][incomplete ])
restrict ;
import proto bgp aspath aspath_regexp
origin any |([igp ][egp ][incomplete ])
[ preference preference ] {
route_filter [ restrict |(preference preference )];
};
EGP importation may be controlled by autonomous system. BGP also supports controlling propagation by
the use of an AS path regular expressions, which are documented in the section on Matching AS paths.
Note that EGP and BGP versions 2 and 3 only support the propagation of natural networks, so the host
and default route filters are meaningless. BGP version 4 supports the propagation of any destination
along with a contiguous network mask.
EGP and BGP both store any routes that were rejected implicitly by not being mentioned in a route filter,
or explicitly with the restrict keyword in the routing table with a negative preference. A negative
preference prevents a route from becoming active, which prevents it from being installed in the forwarding
table, or exported to other protocols. This alleviates the need to break and re-establish a session upon
reconfiguration if importation policy is changed.
Importing routes from an RIP, HELLO and Redirects
import proto rip | hello | redirect
[(interface interface_list )|(gateway gateway_list )]
restrict ;
import proto rip | hello | redirect
[(interface interface_list )|(gateway gateway_list )]
[ preference preference ] {
route_filter [ restrict |(preference preference )];
};
The importation of RIP, HELLO and Redirect routes may be controlled by any of protocol, source interface
and source gateway. If more than one is specified, they are processed from most general (protocol) to most
specific (gateway).
RIP and HELLO do not support the use of preference to choose between routes of the same protocol. That
is left to the protocol metrics. These protocols do not save routes that were rejected since they have short
update intervals.
Importing routes from OSPF
import proto ospfase [ tag ospf_tag ] restrict ;
import proto ospfase [ tag ospf_tag ]
[ preference preference ] {
route_filter [ restrict |(preference preference )];
HP-UX 11i Version 3: February 2007 − 44 − Hewlett-Packard Company 171