Cisco Cisco IOS Software Release 12.0(22)S

To allow the advertising of IP prefixes of connected networks in link-state packet (LSP) advertisements 
per Intermediate System-to-Intermediate System (IS-IS) interface

, 

use

 

the isis advertise-prefix 

command in interface configuration mode. To prevent IP prefixes of connected networks from being 
advertised, use the no form of this command.

This command has no arguments or keywords.

Enabled; IP prefixes are advertised.

Interface configuration

The no isis advertise-prefix command is an IS-IS mechanism to exclude IP prefixes of connected 
networks from LSP advertisements, thereby reducing IS-IS convergence time. 

Configuring the no form of this command per IS-IS interface is a small-scale solution to reduce IS-IS 
convergence time because fewer prefixes will be advertised in the router nonpseudonode LSP. 

An alternative to this command is the 

 command. The latter is a scalable solution 

because it is configured per IS-IS instance.

The following example uses the no isis advertise-prefix command on Ethernet interface 0. Only the IP 
address of loopback interface 0 is advertised. 

!

interface loopback 0

 ip address 192.168.10.1 255.255.255.255

 no ip directed-broadcast

!

interface Ethernet 0

 ip address 192.168.20.1 255.255.255.0

 no ip directed-broadcast

 ip router isis 

 no isis advertise-prefix

!

!.

!.

12.0(22)S

This command was introduced.

12.3(2)T

This command was integrated into Cisco IOS Release 12.2(27)SBC.

12.2(27)SBC

This command was integrated into Cisco IOS Release 12.2(27)SBC.