Primary Active Manager Down in Exchange 2013

Hi All,

I have 2 Exchange Server and both installed CAS and Mailbox Access roles.

And i have DAG configured in both servers for Mailbox server HA. And Enabled Replication for our Databases.

My Question is:

What will going to happen if Primary Active Manager is going down in 2 node exchange server?

How to we make sure all our Exchange client connectivity and Mail flow is happening from Second Exchange server?

Thanks,

Mani L

Mani L