OWA not accessible in one of the CAS server

Hi,

We have 2 CAS server using NLB between them. If we try to access owa from internal or external, we are able to access only on 1 server and if we disable the working server.  We are getting time out for owa.

If i browse the server https://servername/owa... this is working fine. 

Can anyone can suggest some troubleshooting steps.

Thanks

Sandeep