Zimbra Internal GAL ZCS OSS 5.0.14

[mohamedsafeek.s]

Dear Friends,

I am facing a different Issue in my I ahve four zimbra servers one LDAP, HUB and two mailbox server every thing is workign fine..I have only internal GAL, but my GAL is not working fine.when users tried to search for GAL they are getting following error.
A network service error has occured
method:search gal request
msg:system failure:unable to search GAL
code:service failure

please help on this
This is only internal gal of zimbra Ldap and In admin console i configured only internal which doesnt have more details to give only select internal in GAL config in ZCS 5.0.14 OSS