Configuring the Simple Network Management Protocol (SNMP)

Configuring SNMP with the SNMP Agent Manager

select a host on which to perform SNMP configuration.
turn the SNMP agent on and off.
configure information about the local system.
configure information about the local community, traps, and SMUX peers.
view SNMP statistics.

The SNMP Agent Manager interface

The SNMP Agent Manager allows you to perform most SNMP configuration graphically. You can start the SNMP Agent Manager in any of these ways:

Double-click on System Administration on the Desktop, then on Networks, then on SNMP Agent Manager.
Start the SCOadmin launcher by entering scoadmin on the command line, then select Networks, then select SNMP Agent Manager.
Enter scoadmin SNMP Agent Manager on the command line.

The SCOadmin SNMP Agent Manager may fail to run with an error of the form:

   Fatal error: building package index for
   `/usr/lib/scoadmin/snmpmgr/generic.tlib' failed: couldn't open
   "/usr/lib/scoadmin/snmpmgr/generic.tndx": permission denied

To resolve this problem, run the SNMP Agent Manager as root. After it has been run once by root, the SNMP Agent Manager can then be run by any user with owner privileges.

For more information on using SCOadmin managers, see ``Administering your system with SCOadmin''.

To configure SNMP:

By default, you configure the local host. To configure a different host, select Host Open Host and choose another host.
Configure system, community, trap, and peer information by choosing items from the Edit menu and editing the appropriate information.
Turn the agent on by selecting Agent Start Agent.

Selecting another host to manage

Select Host Open Host.
Enter the host name and click on OK, or click on Select to view a list of available hosts, then:
Choose a host name from the list and click on OK.
Enter the host name in the ``Selection'' field and click on OK.

To limit the list to those hosts matching a certain pattern, enter the pattern (including wildcard characters) in the ``Filter'' field, then click on Filter. Then, select the host name from the list and click on OK.

To sort the list by name or address, click on the appropriate radio button.

Configuring the SNMP ``system'' group

The system group contains the basic information that the SNMP agent needs. These are:

The types of SNMP and TCP/IP currently installed.
The object identifier of the agent.
The name of the person responsible for maintaining the system.
The physical location of the system.
A list of reserved SMUX classes.

Generally, only the latter three items need to be updated.

Enter the appropriate information in each field, and click on OK when done.

The last item, SMUX reserved classes, allows you to specify those SMUX MIB classes that may only be managed by the local agent. Any classes not listed here may be, but will not necessarily be, managed by other SNMP agents.

When you make changes to the system group using the SNMP Agent Manager, the information is placed into the file /etc/snmpd.conf:

Sample snmpd.conf file

   descr=SCO TCP/IP Runtime Release 2.0.0
   objid=SCO.1.2.0.0
   contact=Trevor Jones x 256
   location=First Floor Computer Room
   smux_reserved=sco

Configuring the SNMP ``communities'' group

An SNMP community is a group of hosts that you can manage as a distinct group with SNMP.

The SNMP communities group contains a list of community/IP address pairs identifying those management stations from which the agent on the local host accepts queries. Along with each pair is an access field that controls whether access is allowed, and if so, whether the access granted is read-only or read-write. In addition, the special community public, with an address of 0.0.0.0, restricts or allows access to all other members of the public community.

With the Community Names Editor of the SNMP Agent Manager, you can:

Add new community/IP pairs and associated privileges. Click on Add, enter the desired information, and click on OK.
Modify a previously configured community/IP pair. Select the pair from the point-and-pick list, click on Modify, modify the desired information, and click on OK.
Delete a previously configured community/IP pair. Select the pair from the point-and-pick list, click on Delete, and click on OK when asked to verify the change.

The changes you make are saved to the file /etc/snmpd.comm when you click on OK in the information screen. By default, this file originally contains one entry: public 0.0.0.0 read. This allows read access to all members of the public community.

The following is an example of /etc/snmpd.comm. In this example, system 132.147.118.6 of community ``mynet.rivers'' is allowed read access only, whereas system 132.147.246.1 of community ``mynet.cities'' is allowed read and write access. Note that the public community default read access has been changed to no access.

Sample snmpd.comm file

   # community    address       access
   #
   public         0.0.0.0       none
   mynet.rivers   132.147.118.6 read
   mynet.cities   132.147.246.1 write

Configuring the SNMP ``trap'' group

The trap group contains a list of community/IP address pairs identifying those management stations to which the agent sends traps following unusual events, such as a ``cold start''. The trap IP port can also be modified; its default value is 162.

With the Trap Configuration Editor of the SNMP Agent Manager, you can:

Add new community/IP pairs and an associated IP port number. Click on Add, enter the desired information, and click on OK.
Modify a previously configured community/IP pair. Select the pair from the point-and-pick list, click on Modify, modify the desired information, and click on OK.
Delete a previously existing community/IP pair. Select the pair from the point-and-pick list, click on Delete, and click on OK when asked to verify the change.

The changes you make are saved to the file /etc/snmpd.trap when you click on OK in the information screen:

Sample snmpd.trap file

   # community      address       port
   #
   mynet.rivers     132.147.118.1 162
   mynet.cities     132.147.246.1 162

Configuring the SNMP ``peers'' group

The peers group contains a list of SMUX peers known to the local SNMP agent. This information is needed only to enable the agent to communicate with a SMUX peer that exports a specific MIB module. Fields include:

Peer Name: The name of the remote system running the SMUX peer.
Object ID: The object ID associated with the particular peer.
Password: A password that the peer must pass to the agent when the peer initiates a relationship with the agent.
Priority: An optional field containing a priority level. The agent uses the priority value to determine which SMUX peer to consult when more than one peer registers the same subtree. Legal values are 0 to (2^31)-1, with a lower number having a higher priority. A ``-1'' can also be used to represent the highest available priority.

NOTE: Because this file contains passwords in standard ASCII text, take care to restrict access to this file.

With the Peers Configuration Editor of the SNMP Agent Manager, you can:

Add new SMUX peers, including their object IDs, passwords, and priorities.
Modify a previously configured SMUX peer. Select the peer from the point-and-pick list, click on Modify, modify the desired information, and click on OK.
Delete a previously configured SMUX peer. Select the peer from the point-and-pick list, click on Delete, and click on OK when asked to verify the change.

The changes you make are saved to the file /etc/snmpd.peers when you click on OK in the information screen:

Sample snmpd.peers file

   #
   # <name>         <object-id>              <password>    [<priority>]
   #
   "gated"     1.3.6.1.4.1.2.3.1.2.1.2     "gated_password"
   "foo"       1.3.6.1.4.1.4.3.99          "aintNoThing"       -1