|
SNMP (Simple Network Management Protocol) is a generic network management tool. An SNMP message is sent to and from a device to gather information or configure the device.
SNMP Message Structure
A message using the SNMP protocol consists of any number of SNMP requests. The message itself can be either a set-request or a get-request. The set-request message is used for configuration, and the get-request message is used for gathering information.
Each request within an SNMP message consists of an entry in the MIB, called an Object Identifier, and a value. The value can be one of many types, for example, integer, or octet (byte) string.
In addition, the SNMP message contains a community string, which is used by the device as a password to give the user clearance to read or write
the information requested. There are generally two community strings used: the read string and the write string. These can be the same or
different. The first is used in a get-request, and the device will only
answer if the read string allows the user to read the information from
the device. The second is used for the set-request and will verify that
the user has permission to modify the configuration of the device.
Using an SNMP MIB Browser
There are many SNMP MIB browser applications available for all different
workstation platforms. For example, Hewlett-Packard has the HP OpenView* software for PC and UNIX workstations.
The typical MIB browser software provides simple network mapping features, and usually provides a graphical interface for laying out the devices on the screen. Some software comes with auto-discovery features, which will automatically acknowledge all devices on the network.
Most MIB browsing software also allows the user to compile various MIB extensions into its database, allowing the user to use a private MIB (supplied by the device vendor) to manage a particular device. Since the MIB browser does not "know" very much about the device management capabilities, this method of management can be slow and painful. When managing device-specific options, it is generally preferable to use any software provided by the device manufacturer.
This applies to:
| 
