Morning AllWe have been getting this constantly under our System event log on our exchange server.Could anyone shed any light on this for me?A Kerberos Error Message was received: on logon session Client Time: Server Time: 8:0:51.0000 6/1/2009 ZError Code: 0x34 KRB_ERR_RESPONSE_TOO_BIGExtended Error: Client Realm: Client Name: Server Realm: "FQDN"Server Name: SMTPSVC/ss-mail11.FQDNTarget Name: SMTPSVC/ss-mail11.FQDNError Text: File: 9Line: ae0Error Data is in record data.CheersJames

Per my knowledge, KRB_ERR_RESPONSE_TOO_BIG error can be safely ignored. It means that response is too big for UDP, and windows will automatically switches to TCP after UDP failed Also, please verify that Kerberos event logging isnt enabled on the server, same symptom will occur if its the case (KB 262177) Notes: The question is more related to windows field, please use Windows Server forum if theres any further question about Kerberos Resources: Kerberos Authentication Tools and Settings Authentication Using UDP Causes Errors