HP-UX Reference (11i v1 00/12) - 4 File Formats (vol 8)

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/build/1111/BRICK/man4/!!!intro.4

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gated.conf(4) gated.conf(4)

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 )];

};

Due to the nature of OSPF, only the importation of ASE routes may be controlled. OSPF intra- and inter-

area routes are always imported into the gated routing table with a preference of 10. If a tag is speciﬁed,

the import clause will only apply to routes with the speciﬁed tag.

It is only possible to restrict the importation of OSPF ASE routes when functioning as an AS border router.

This is accomplished by specifying an export ospfase clause. Speciﬁcation of an empty export clause may

be used to restrict importation of ASEs when no ASEs are being exported.

Like the other interior protocols, preference can not be used to choose between OSPF ASE routes, that is

done by the OSPF costs. Routes that are rejected by policy are stored in the table with a negative prefer-

ence.

HP-UX Release 11i: December 2000 − 44 − Section 4−−115

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