Use the following syntax to configure an area ID also called an address. A maximum of three area IDs can be configured.
config>router# isis
area-id area-address
config>router>isis#
config>router>isis# area-id 49.0180.0001
config>router>isis# area-id 49.0180.0002
config>router>isis# area-id 49.0180.0003
A:ALA-A>config>router>isis# info
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area-id 49.0180.0001
area-id 49.0180.0002
area-id 49.0180.0003
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A:ALA-A>config>router>isis#