I'm on centos, and I need to check that an AD server is running (is in another host). Which is the simplest way to check ldap (AD) is running? I have an application where I need to synchronize some users account with AD, but suddenly I'm getting 0 users found. I don't know much about AD and LDAP, I just tested with:
[root@mysystem]# ldapsearch -x
ldap_sasl_bind(SIMPLE): Can't contact LDAP server (-1)
Is that enough to check that LDAP is down? Or can it be another reason?
Can't contact LDAP server (-1) doesn't explicitly mean that your AD isn't "running".
There are few things that could cause that error.
You might also have some misconfiguration, or something else blocking you to contact your AD.
However, if you can ldapsearch with some anonymous request (with -x) just before, I suppose that's an acceptable way to check.
If I refer myself to this previous post How to test a LDAP connection from a client, the test you're currently using should be fine. (considering it was working before, and it's a connectivity issue, and not a misconfiguration)
Make yourself sure that anonymous authentication are enable, and you can actually query the AD with it.
