A stealth change in the 7.1 release is the support of V3 of the Simple Network Management Protocol (SNMP). You won't find this secret documented clearly in the Information Center and it's not covered in the 7.1 overview information. It’s covered in the 7.1 Technical Overview Redbooks publication.
Simple Network Management Protocol (SNMP) version 3 is the current standard version of SNMP. SNMP has been available on i (and it's predecessors) for years, but hadn’t been updated since its original availability. The primary motivation for the update to SNMP in 7.1 was to support IPv6, but SNMPv3 also incorporates the use of user-based authentication and data privacy.
You must enable the system to handle SNMPv3 requests. Do this by using the Change SNMP Attributes (CHGSNMPA) command, with the “Allow SNMPv3 support” (ALWSNMPV3) parameter set to *YES. The default is *NO, so until you specifically change the attributes, you won’t be using v3. The SNMP server must be ended and then started again for this change to take effect. If you change this attribute to allow SNMPv3, it won’t affect any existing SNMP applications that you may have, since older version packets will still be accepted and handled as they were before.
User-based authentication for SNMP requires that you use the Add User for SNMP (ADDUSRSNMP) command. This command is new in 7.1, and there are the corresponding change and remove commands. An SNMP user isn’t the same as an IBM i user profile. Rather, SNMP users are added and maintained separately. SNMP users allow for authentication and privacy for SNMP request/response flows, and you can restrict access to management information base (MIB) objects based upon the SNMP user names.
Finally, 7.1 also provides support for several new MIBs:
• RFC 4293 - MIB for the Internet Protocol (IP)
• RFC 4292 - IP Forwarding Table MIB
• RFC 4022 - MIB for the Transmission Control Protocol (TCP)
• RFC 4113 - MIB for the User Datagram Protocol (UDP)
Simple Network Management Protocol (SNMP) version 3 is the current standard version of SNMP. SNMP has been available on i (and it's predecessors) for years, but hadn’t been updated since its original availability. The primary motivation for the update to SNMP in 7.1 was to support IPv6, but SNMPv3 also incorporates the use of user-based authentication and data privacy.
You must enable the system to handle SNMPv3 requests. Do this by using the Change SNMP Attributes (CHGSNMPA) command, with the “Allow SNMPv3 support” (ALWSNMPV3) parameter set to *YES. The default is *NO, so until you specifically change the attributes, you won’t be using v3. The SNMP server must be ended and then started again for this change to take effect. If you change this attribute to allow SNMPv3, it won’t affect any existing SNMP applications that you may have, since older version packets will still be accepted and handled as they were before.
User-based authentication for SNMP requires that you use the Add User for SNMP (ADDUSRSNMP) command. This command is new in 7.1, and there are the corresponding change and remove commands. An SNMP user isn’t the same as an IBM i user profile. Rather, SNMP users are added and maintained separately. SNMP users allow for authentication and privacy for SNMP request/response flows, and you can restrict access to management information base (MIB) objects based upon the SNMP user names.
Finally, 7.1 also provides support for several new MIBs:
• RFC 4293 - MIB for the Internet Protocol (IP)
• RFC 4292 - IP Forwarding Table MIB
• RFC 4022 - MIB for the Transmission Control Protocol (TCP)
• RFC 4113 - MIB for the User Datagram Protocol (UDP)
I am trying to find out what version of SNMP is the default implementation in the following versions of i5/OS:
version 5.4
version 6.1
version 7.1
...I know v7 supports SNMP v3, but what version does it use if Allow SNMP v3 support is not turned on?
Thanks,
Ernie
Posted by: Ernie Moskovics | December 12, 2011 at 12:08 PM
HI Ernie,
The default version for all releases, including 7.1, is SNMP version 1.
In 7.1, setting "Allow SNMPv3 support" on means that the SNMP agent will accept and handle SNMPv3 packets if they are received by the agent. The IBM i SNMP agent always responds with the same version that it received from the manager.
Currently, the IBM i SNMP manager APIs only support SNMP version 1 packets.
Dawn
Posted by: Dawn | December 13, 2011 at 07:41 AM