HP-UX Routing Services Administrator's Guide HP-UX 11i v2, HP-UX 11i v3 (B2355-91153, November 2011)

You must specify the defaults statements in the OSPF protocol configuration only for AS boundary
routers. These statements specify how external routing information is handled by the OSPF protocol.
You can define the following in the defaults statements:
• preference specifies the preference value given to the ASE routes imported from other
autonomous systems. The preference value determines the order of routes to the same
destination in the routing table. gated allows one route to a destination per protocol for each
AS. In case of multiple routes, the route used is determined by the lowest preference value
(see “Specifying Route Preference” (page 46) for more information). If a preference value is
not specified, ASE routes are imported with a preference of 150.
◦ Default: 150
◦ Range: 0 (most preferred) – 255 (least preferred)
• cost specifies the cost associated with an OSPF route that is exported to other AS boundary
routers.
◦ Default: 0
◦ Range: 0 – 65535
• tag specifies an OSPF tag placed on all routes exported by gated into OSPF. You can tag
each external route by the AS boundary router to identify the source of the routing information.
The tag value can be an unsigned 31-bit number. You can also specify tag as as_tag,
where as_tag is an unsigned 12-bit number that is automatically assigned.
• type determines how ASE routes imported into OSPF are treated. Type 1 routes must be
routes from internal gateway protocols with external metrics that are directly comparable to
OSPF metrics. When OSPF selects a route, OSPF uses the type 1 route’s external metric and
adds the OSPF internal cost to the AS border router. Type 2 routes must be routes from external
gateway protocols with metrics that are not comparable to OSPF metrics. When OSPF selects
a route, OSPF ignores a type 2 route’s metric and uses only the OSPF internal cost to the AS
border router.
◦ Default: 1
• exportlimit specifies the rate at which ASE routes are imported into the gated routing
table for each exportinterval.
◦ Default: 100 (ASE routes)
◦ Range: 0 – 65535
• exportinterval specifies the interval (in seconds) between ASE exports into OSPF.
◦ Default: 1 (second)
◦ Range: 0 – 2147483647
Sample OSPF Configuration
Figure 16 shows an example of two areas. Area 1 is a non-stub area, while area 2 is configured
as a stub area. Node B is an area border router between the two areas.
40 Configuring gated