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Implementing Routing Policy on Cisco IOS XR Software
Information About Implementing Routing Policy on Cisco IOS XR Software
RC-383
Cisco IOS XR Routing Configuration Guide
OL-14356-01
Allocate-Label
The allocate-label attach point provides increased control based on various attribute match operations.
This attach point is typically used in inter-AS option C to decide whether the label should be allocated
or not when sending updates to the neighbor for the IPv4 labeled unicast address family. The attribute
setting actions supported are for pass and drop.
The following example shows how to configure a route policy that passes the prefix 0.0.0.0 with prefix
length 0. Label allocation happens only if prefix 0.0.0.0 exists.
route-policy label_policy
if destination in (0.0.0.0/0) then
pass
endif
end-policy
router bgp 2
vrf vrf1
rd auto
address-family ipv4 unicast
allocate-label route-policy label-policy
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Neighbor-ORF
The neighbor-orf attach point provides the filtering of incoming BGP route updates using only
prefix-based matching. In addition to using this as an inbound filter, the prefixes and disposition (drop
or pass) are sent to upstream neighbors as an Outbound Route Filter (ORF) to allow them to perform
filtering.
The following example shows how to configure a route policy orf-preset and apply it to the neighbor
ORF attach point. The prefix of the route is dropped if it matches any prefix specified in orf-preset
(211.105.1.0/24, 211.105.5.0/24, 211.105.11.0/24). In addition to this inbound filtering, BGP also sends
these prefix entries to the upstream neighbor with a permit or deny so that the neighbor can filter updates
before sending them on to their destination.
prefix-set orf-preset
211.105.1.0/24,
211.105.5.0/24,
211.105.11.0/24
end-set
route-policy policy-orf
if orf prefix in orf-preset then
drop
endif
if orf prefix in (211.105.3.0/24, 211.105.7.0/24, 211.105.13.0/24) then
pass
endif
router bgp 2
neighbor 1.1.1.1
remote-as 3
address-family ipv4 unicast
orf route-policy policy-orf
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.
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