Specifications
Implementing IS-IS on Cisco IOS XR Software
How to Implement IS-IS on Cisco IOS XR Software
RC-207
Cisco IOS XR Routing Configuration Guide
Step 7
summary-prefix 
address/prefix-length 
[level {1 
| 2}]
or
summary-prefix 
ipv6-prefix/prefix-length 
[level 
{1 | 2}]
Example:
RP/0/RP0/CPU0:router(config-isis-af)# 
summary-prefix 10.1.0.0/16 level 1
or
RP/0/RP0/CPU0:router(config-isis-af)# 
summary-prefix 3003:xxxx::/24 level 1
(Optional) Allows a Level 1-2 router to summarize Level 1 
IPv4 and IPv6 prefixes at Level 2, instead of advertising the 
Level 1 prefixes directly when the router advertises the 
summary.
• This example specifies an IPv4 address and mask.
or
• This example specifies an IPv6 prefix, and the 
command must be in the form documented in RFC 2373 
in which the address is specified in hexadecimal using 
16-bit values between colons.
• Note that IPv6 prefixes must be configured only in the 
IPv6 router address family configuration submode, and 
IPv4 prefixes in the IPv4 router address family 
configuration submode.
Step 8
maximum-paths 
route-number
Example:
RP/0/RP0/CPU0:router(config-isis-af)# 
maximum-paths 16
(Optional) Configures the maximum number of parallel 
paths allowed in a routing table.
Step 9
distance 
weight
 [
address
/
prefix-length
[
route-list-name
]]
Example:
RP/0/RP0/CPU0:router(config-isis-af)# distance 
90
(Optional) Defines the administrative distance assigned to 
routes discovered by the IS-IS protocol.
• A different administrative distance may be applied for 
IPv4 and IPv6.
Command or Action Purpose










