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Purpose
Command or Action
RP/0/RP0/CPU0:router(config)# router isis isp
• 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:
Step 3
RP/0/RP0/CPU0:router(config-isis)#address-family
ipv4 unicast
(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/RP0/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.
(Optional) Configures incremental IS-IS ISPF to calculate
network topology.
ispf
[
level
{
1
|
2
}]
Example:
Step 5
RP/0/RP0/CPU0:router(config-isis-af)# ispf
commit
Step 6
(Optional) Displays how often and why the router has run
a full SPF calculation.
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
]
Step 7
Example:
RP/0/RP0/CPU0:router# show isis instance 1 spf-log
ipv4
Customizing Routes for IS-IS
This task explains how to perform route functions that include injecting default routes into your IS-IS routing
domain and redistributing routes learned in another IS-IS instance. This task is optional.
Routing Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
231
Implementing IS-IS
Customizing Routes for IS-IS