Guide here.
ktpass -princ DNS/infoblox.corp.local@CORP.LOCAL -mapuser svc_dns@corp.local -pass YourP@ssword123 -crypto AES256-SHA1 -ptype KRB5_NT_PRINCIPAL -out infoblox.keytab
or
ktpass -princ DNS/infoblox.corp.local/@CORP.LOCAL -mapuser svc_dns@corp.local -pass YourP@ssword123 -crypto AES256-SHA1 -ptype KRB5_NT_PRINCIPAL -out infoblox.keytab