Cisco ASR 9000 Series

SUMMARY STEPS
1.
configure
2.
router isis instance-id
3.
address-family { ipv4 | ipv6 } [ unicast ]
4.
spf-interval {[ initial-wait initial | secondary-wait secondary | maximum-wait maximum ] ...}
[ level { 1 | 2 }]
5.
ispf [ level { 1 | 2 }]
6.
commit
7.
show isis [ instance instance-id ] [[ ipv4 | ipv6 | afi-all ] [ unicast | safi-all ]] spf-log [ level { 1
| 2 }] [ ispf | fspf | prc | nhc ] [ detail | verbose ] [ last number | first number ]
DETAILED STEPS
PurposeCommand or Action
configure
Step 1
Enables IS-IS routing for the specified routing instance, and
places the router in router configuration mode.
router isis instance-id
Example:
RP/0/RSP0/CPU0:router(config)# router isis isp
Step 2
•
You can change the level of routing to be performed
by a particular routing instance by using the is-type
router configuration command.
Specifies the IPv4or IPv6 address family, and enters router
address family configuration mode.
address-family { ipv4 | ipv6 } [ unicast ]
Example:
RP/0/RSP0/CPU0:router(config-isis)#address-family
ipv4 unicast
Step 3
(Optional) Controls the minimum time between successive
SPF calculations.
spf-interval {[ initial-wait initial | secondary-wait
secondary | maximum-wait maximum ] ...} [ level { 1
| 2 }]
Step 4
•
This value imposes a delay in the SPF computation
after an event trigger and enforces a minimum elapsed
time between SPF runs.
Example:
RP/0/RSP0/CPU0:router(config-isis-af)#
spf-interval initial-wait 10 maximum-wait 30
•
If this value is configured too low, the router can lose
too many CPU resources when the network is unstable.
•
Configuring the value too high delays changes in the
network topology that result in lost packets.
•
The SPF interval does not apply to the running of the
ISPF because that algorithm runs immediately on
receiving a changed LSP.
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
380
Implementing IS-IS
Setting SPF Interval for a Single-Topology IPv4 and IPv6 Configuration