Cisco NCS 5500 Series

This table summarizes which operations are valid and where they are valid.
Table 5: Restricted BGP Operations by Attach Point
redistributionaggregationexportimportCommand
n/an/aeBGP
only
eBGP
only
prepend as-path most-recent
n/an/aeBGP
only
eBGP
only
replace as-path
forbiddenforbiddeneBGP
only
forbiddenset med igp-cost
n/an/aforbiddenn/aset weight
forbiddenn/aforbiddenforbiddensuppress
Default-Information Originate
The default-information originate attach point allows the user to conditionally inject the default route 0.0.0.0/0
into the OSPF link-state database, which is done by evaluating the attached policy. If any routes in the local
RIB pass the policy, then the default route is inserted into the link-state database.
The following example shows how to generate a default route if any of the routes that match 10.0.0.0/8 ge 8
le 25 are present in the RIB:
route-policy ospf-originate
if rib-has-route in (10.0.0.0/8 ge 8 le 25) then
pass
endif
end-policy
router ospf 1
default-information originate policy ospf-originate
.
.
.
OSPF Policy Attach Points
This section describes each of the OSPF policy attach points and provides a summary of the OSPF attributes
and operators.
Redistribute
The redistribute attach point within OSPF injects routes from other routing protocol sources into the OSPF
link-state database, which is done by selecting the routes it wants to import from each protocol. It then sets
the OSPF parameters of cost and metric type. The policy can control how the routes are injected into OSPF
by using the set metric-type or set ospf-metric command.
The following example shows how to redistribute routes from IS-IS instance instance_10 into OSPF instance
1 using the policy OSPF-redist. The policy sets the metric type to type-2 for all redistributed routes. IS-IS
routes with a tag of 10 have their cost set to 100, and IS-IS routes with a tag of 20 have their OSPF cost set
Routing Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x
177
Implementing Routing Policy
Default-Information Originate