openldap mirror mode replication does the versions of client matter

Hi,

I have set up mirror mode replication with both my masters running 2.4.39 version.

I have around 1000 clients connecting. The versions of openldap on these clients varies from 2.3.43( thats really old I know) , 2.4.23 and few have 2.4.39.

My problem is the ldap servers almost hangs or freezes when the clients start connecting. In the error logs , I see this pattern " conn=6005 fd=4199 closed (TLS negotiation failure "

Is this something to do with the client versions and will upgrading help. I was skeptical as this is in production.

One more question, In mirror mode is it ok to have more than 2 masters.

Thanks,

Rakesh