連接12cR2 PDB報錯ORA-28040/ORA-01017

測試環境安裝了一套12cR2的數據庫，想要通過PL/SQL developer連接上數據庫，但是報錯

ORA-28040: No matching authentication protocol

上網查了原因：Oracle 12c的參數SQLNET.ALLOWED_LOGON_VERSION默認等于11。當我們使用11g JDBC之前版本的thin驅動連接的時候，就會報錯。

于是按網上的方法解決方法來做：

在數據庫服務器上的oracle/network/admin/sqlnet.ora文件添加一行SQLNET.ALLOWED_LOGON_VERSION=8

修改之后再次連接卻又報錯ORA-01017: invalid username/password; logon denied

確認用戶名和密碼是沒問題的，但就是連接不上，在服務器端就可以連接

[oracle@t13s ~]$ sqlplus pdbadmin@pdb1

SQL*Plus: Release 12.2.0.1.0 Production on Fri Mar 17 10:25:22 2017

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

Enter password: 
Last Successful login time: Thu Mar 16 2017 20:28:26 +08:00

Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

PDBADMIN@pdb1>

于是在MOS上搜索相關文檔，查到這樣一篇文章Client / Server Interoperability Support Matrix for Different Oracle Versions (文檔 ID 207303.1)

從文章中可以看出只有11.2.0.3及以上的版本的客戶端才能連接12.2版本的服務端。再檢查本地的Oracle客戶端的版本是11.2.0.1，原來是客戶端版本太低了，安裝12.1版本的客戶端，順利登錄。

MOS文章大致內容如下：

Client Version	Server Version
	12.2.0#10	12.1.0	11.2.0	11.1.0	10.2.0	10.1.0	9.2.0
12.2.0	Yes	Yes	Yes	No	No	No#3	No#3
12.1.0	Yes	Yes	Yes	Was	MDS #7	No#3	No#3
11.2.0	Yes#9	Yes	Yes	Was	MDS #7	No	Was #5
11.1.0	No	Was	Was	Was	Was #7	Was #6	Was #5
10.2.0	No	MDS #7	MDS #7	Was #7	MDS	Was	Was #5
10.1.0#4	No	No	Was #6	Was #6	Was	Was	Was
9.2.0	No	No#8	Was #5	Was #5	Was #5	Was	Was

Key:

Yes	Supported
ES	Supported but fixes only possible for customers with Extended Support .
LES or MDS	Supported but fixes only possible for customer with a valid Limited Extended Support or Market-Driven Support contract respectively.
Was	Was a supported combination but one of the releases is no longer covered by any of Premier Support, Primary Error Correct support, Extended Support, nor Extended Maintenance Support. Fixes are no longer possible.
No	Has never been Supported

Specific Notes:

#1 - See Note:207319.1#2 - An ORA-3134 error is incorrectly reported if a 10g client tries to connect to an 8.1.7.3 or lower server. See Note:3437884.8 .#3 - An ORA-3134 error is correctly reported when attempting to connect to this version.#4 - There are problems connecting from a 10g client to 8i/9i where one is EBCDIC based. See Note:3564573.8#5 - For connections between 10.2 (or higher) and 9.2 the 9.2 end MUST be at 9.2.0.4 or higher. Connections between 10.2 (or higher) and 9.2.0.1, 9.2.0.2 or 9.2.0.3 have never been supported.#6 - For connections between 11.1 (or higher) database server and 10.1 / 10.2 database server across a database link the 10g end MUST be at 10.1.0.5 / 10.2.0.2 (or higher) respectively in order to use PLSQL between those versions. (This does not apply to normal 11g clients to 10g database server only server to server and a few very specific client products, such as Oracle Forms). See Note:4511371.8 for more details.#7 - For database link connections between 11.1 (or higher) and 10.2 the 10g end MUST be at 10.2.0.2 (or higher) in order to use PLSQL between those versions. See Note:4511371.8 for more details.#8 - Attempting to connect from 9.2 to 12.1 will fail with an "ORA-28040: No matching authentication protocol" error.#9 - 11.2.0.3 or 11.2.0.4 only. We do not support any 11.2 client interoperability with Oracle Database Exadata Express Cloud Service#10 - Includes Oracle Database Exadata Express Cloud Service - see Note:2183770.1 for additional details

General Notes:

1. For database links between different Oracle versions connections must be supported in BOTH directions in the matrix above.
   eg: As 11.2 -> 10.1 is not supported then database links between these version are not supported in either direction.
   

2. Unsupported combinations may appear to work but can encounter errors for particular operations. The fact that they appear to work should not be relied upon - issues on unsupported combinations will not be investigated.

3. Since new database servers are compatible with a limited set of older OCI clients, it may not be necessary to upgrade the client software when upgrading the database. However, some new features may not work without upgrading the client software. For example, an Oracle 10.2 client is able to connect to an 11.2 database, but is not able to take advantage of newer features such as Client Result Cache (introduced in 11.1).

4. Oracle Applications , or other Oracle products, may have supported configurations not listed in the matrix above.

5. The matrix above also applies between different platforms and between 32/64 bit releases of Oracle client / server except where any Oracle platform desupport notice indicates otherwise .

6. Unix BEQUEATH (BEQ) connections are NOT supported between different releases. eg: Client 10.2 is not supported to make an Oracle Net connection to a 11.2 server using the BEQ protocol adapter regardless of the interoperability support listed above. See Note:364252.1 for more details.