Importation of routes from routing protocols and installation of the routes in
gated's
routing database are controlled by import statements. The format of
an import statement varies depending on the source protocol.
In all cases, one of two keywords may be specified to control how routes
compete with other protocols:
restrict
Specifies that the routes are not desired in the routing table. In some
cases, this means that the routes are not installed in the routing table. In
others, it means that they are installed with a negative preference; this
prevents them from becoming active so they will not be installed in the
forwarding table or exported to other protocols.
preference preference
Specifies the preference value used when comparing this route to other
routes from other protocols. The route with the lowest preference
available of any given route becomes the active route, is installed in the
forwarding table, and is eligible to be exported to other protocols. The
default preferences are configured by the individual protocols.
All the formats below with the variable route_filter allow
route filters. See
``gated route filtering''
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.