IS-IS CLI levels

The CLI includes various levels of commands for IS-IS. The figure below illustrates these levels.

IS-IS CLI levels

The following IS-IS CLI configuration modes are available

• ISIS router configuration mode: A global level for the configuration of the IS-IS protocol. At this level, all IS-IS configurations apply to IPv4 and IPv6.
• ISIS address-family IPv4 unicast configuration mode: Commands entered in ISIS address-family IPv4 unicast configuration mode apply only to IS-IS IPv4 configurations.
• ISIS address-family IPv6 unicast configuration mode: Commands entered in ISIS address-family IPv6 unicast configuration mode apply only to IS-IS IPv6 configurations.
• Interface subtype configuration mode: Various IS-IS options are configured on a specified interface.

Refer to the relevant Command Reference for more information on each of these configuration modes and for information on all of the commands accessed in these configuration modes.

Each address family configuration level allows you to access commands that apply to that particular address family only. To enable a feature in a particular address family, you must specify any associated commands for that feature in that particular address family. You cannot expect the feature, which you may have configured in the IPv4 IS-IS unicast address family, to work in the IPv6 IS-IS unicast address family unless it is explicitly configured in the IPv6 IS-IS unicast address family.