Server5 wont support 10.6.8 or earlier...

I am going crazy... I updated t0 SERVER 5 and everything was ok I also updated some of my computers in my network to el CApitan and they see each other. but I have around 8 computers on 10.6.8 and wont upgrade anymore...

The problem is that they wont see the SERVER...

I can not log in using a valid user or password...

I need help... How do I make those old computers log into my network??

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