SSL for Exchange 2013 with ARR

Hi,

Need advice on the number of SSL i would need to purchase.

I know that I require to have a SSL with example: mail.domain.com & autodiscover.domain.com

How about the ARR server that I will be setting up. Refer to http://social.technet.microsoft.com/Forums/exchange/en-US/fe8d1aae-a3c9-432a-a139-7b770cb07576/new-exchange-2013-setup-vmware?forum=exchangesvrdeploy

do i need to have a SSL cert for the ARR server?

Thanks in advance!