There are continual event id 36888 in each DC's log as follows: ""A fatal alert was generated and sent to the remote endpoint. This may result in termination of the connection. The TLS protocol defined fatal error code is 10. The Windows SChannel error state is 1203."
In addition, dcdiag displays (In part)
Starting test: SystemLog
An error event occurred. EventID: 0x00009018
Time Generated: 09/03/2016 09:01:15
Event String:
A fatal alert was generated and sent to the remote endpoint. This ma
y result in termination of the connection. The TLS protocol defined fatal error
code is 10. The Windows SChannel error state is 1203.
An error event occurred. EventID: 0x00009018
Time Generated: 09/03/2016 09:01:15
Event String:
A fatal alert was generated and sent to the remote endpoint. This ma
y result in termination of the connection. The TLS protocol defined fatal error
code is 10. The Windows SChannel error state is 1203.
......................... WWE-DC failed test SystemLog
Both DCs get them, but one side gets way more. Each is 2012 R2 and has Essentials role installed. VPN is full time between two sites at close to 100MBS.
My questions are a) what is the cause of this, i.e., where can I find additional information to pinpoint the cause, and b) what do I do with it to fix the issue>
389 (LDAP)
636 (LDAPS)
3268 (LDAP GC)
3269 (LDAPS GC)
There is a list of Schannel error codes here. In your case you're receiving error 10, which would be SSLv3. Some applications will try an LDAPS bind first and then fall back to LDAP which can generate these errors if you're not offering up LDAPS. If you do not offer LDAPS you can ignore these errors.