Specify the OSPF Tag

By default, no OSPF tag strings are associated with aggregate routes. You can specify an OSPF tag string by including the tag option at the [edit routing-options aggregate (defaults | route)] hierarchy level (for routing instances, include the option at the [edit routing-instances routing-instance-name routing-options aggregate (defaults | route)] hierarchy level):

[edit routing-options aggregate (defaults | route)] 

tag string;