how to re-connect a broker client

I see one of our broker client is not connected. Can you please suggest how to re-connect the client. I found no info in the Broker_Admin guide. Should I have to re-start the IS?

I see info on how to dis-connet the client. But not for connecting it.

Regards,
Sunny

yes, I have the same question.
usually, I restart IS to get broker client connect.