new RODC in other site: LDAP Error 81(0x51): Server Down

Hi,

I installed a new RODC in an other site and when I know try to do the replication from one of my existing DC in my site:

Repadmin /showrepl DC

    LDAP Error 81(0x51): Server Down
    Server Win32 Error 0(0x0):
    Extended Information:

Repadmin /bind

LDAP Error 81(0x51): Server Down
Server Win32 Error 0(0x0):
Extended Information:

I'm able to start the replication from the RODC through Sites and Services, but not from my local DC.

I got the error rpc Server not available.