gtpc1m2k | Transmission Control Protocol/Internet Protocol |
TPF support for the SNMP agent is a User Datagram Protocol (UDP) server that responds to requests received from SNMP managers. The TPF Internet daemon monitors the network for SNMP requests destined for the SNMP agent server. SNMP requires the agent to be bound to well-known port 161.
The TPF SNMP agent supports SNMP Version 1. The TPF SNMP agent supports and maintains the Management Information Base-II (MIB-II) database of network statistics and data for TCP/IP native stack support networks. The MIB-II database splits the MIB variables into groups, and only the groups pertaining to TPF are supported by TPF. You must define some MIB variables in the SNMP configuration file, which resides on the TPF file system as /etc/snmp.cfg. See Creating the SNMP Configuration File for more information about creating the /etc/snmp.cfg SNMP configuration file, and see Appendix G, Management Information Base Variables for a detailed list of all the MIB-II groups and variables that the TPF system supports.
In addition to the predefined MIB-II variables supported by the TPF system, you can provide your own enterprise-specific MIB variables. These enterprise-specific MIB variables allow you to track information that is of specific interest to you in managing your network. A user exit, UMIB, is provided to allow you to process these enterprise-specific MIB requests. See User MIB Variables for more information about enterprise-specific MIB variables. See TPF System Installation Support Reference for information about the UMIB user exit.
The TPF system can also send the following predefined SNMP trap PDUs:
TPF SNMP agent support also allows you to send your own enterprise-specific trap PDUs by using the ITRPC macro or the tpf_itrpc C/C++ function. You can send enterprise-specific traps to one or more SNMP managers defined in the /etc/snmp.cfg SNMP configuration file. If desired, you can disable SNMP traps, which prevents all SNMP traps from being sent to the network. See TPF General Macros for more information about the ITRPC macro and see the TPF C/C++ Language Support User's Guide for more information about the tpf_itrpc C/C++ function.
The TPF system processes and responds to all GETREQUEST and GETNEXTREQUEST PDUs received. All SETREQUEST PDUs received by TPF are rejected with a NOSUCHNAME error code because of the security risk involved when allowing MIB variables in TPF to be set by a remote SNMP manager.
The TPF system uses the MIB-II database to provide its MIB variables and maintains it in a core memory table. Core memory for the MIB is allocated during restart and reinitialized after an IPL. Each processor in a loosely coupled complex has and maintains its own MIB. See Appendix G, Management Information Base Variables for a list of all the MIB-II variables supported by the TPF system.
The MIB-II database consists of many units of information that provide performance and statistical information about the TCP/IP networks connected to the TPF system. The TPF system updates and maintains the MIB-II variables for networks established with TPF TCP/IP native stack support. Each MIB-II variable has a unique name in Abstract Syntax Notation One (ASN.1) format called an object identifier, or object ID, that is used when a request PDU is received from the network to retrieve the MIB-II variable information. The MIB-II database defines the following SNMP groups:
Some of these groups contain table variables, and the variables in the table pertain to multiple entities. For example, the interfaces group mentioned previously contains an interface table with statistical information for each interface or IP address in the TPF system.