Exchange 2013 installed with Exchange 2010

  Hi,

  I am running Exchange 2010 and Exchange 2013 on sama domain. I need some answers before I continue.

 1) Can I  move mailboxes gradually to Exchange 2013 without problem? Is there any thing I shuld be aware of regarding that?

 2) Can I use the same network for DAG on Exchange 2013 as I am using on Exchange 2010, I am using whole Cnet fore this purpose. Having poblem creating a  new DAG group on 2013. Maybe it will be solved by installing Exchange 2013 CU2??

 3)  Can I use ECP for administering both Ex 2010 and Ex, like creating users and all administration regarding that.

 4) Should I get new certificate for CAS service now og can I pospone it?

 thanks.

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