Cisco NCS 5500 Series

The Level 1 instance is propagating routes to the Level 2 instance using redistribution. Note that the
administrative distance is explicitly configured higher on the Level 2 instance to ensure that Level
1 routes are preferred.
Attached bit is being set for the Level 1 instance since it is redistributing routes into the Level 2
instance. Therefore, instance “1” is a suitable candidate to get from the area to the backbone.
router isis 1
is-type level-2-only
net 49.0001.0001.0001.0001.00
address-family ipv4 unicast
distance 116
redistribute isis 2 level 2
!
interface HundredGigE 0/3/0/0
address-family ipv4 unicast
!
!
router isis 2
is-type level-1
net 49.0002.0001.0001.0002.00
address-family ipv4 unicast
set
-attached
-bit
!
interface HundredGigE 0/1/0/0
address-family ipv4 unicast
Set Priority for Adding Prefixes to RIB
This optional task describes how to set the priority (order) for which specified prefixes are added to the RIB.
The prefixes can be chosen using an access list (ACL), prefix list, or by matching a tag value.
SUMMARY STEPS
1. configure
2. router isis instance-id
3. address-family { ipv4 | ipv6 } [ unicast ]
4. metric-style wide [ transition ] [ level { 1 | 2 }]
5. spf prefix-priority [ level { 1 | 2 }] { critical | high | medium } { access-list-name | tag tag }
6. commit
DETAILED STEPS
Step 1 configure
Step 2 router isis instance-id
Example:
RP/0/RP0/CPU0:router(config)# router isis isp
Routing Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x
15
Implementing IS-IS
Set Priority for Adding Prefixes to RIB