SNMP Interface

Managing Networks

Managing Networks

The SNMP standard MIB is used to manage basic network objects. In addition, SNMP is flexible enough that it can support a wide variety of MIBs describing other device functions and interfaces. For example, the Access Navigator uses the standard MIB (RFC 1406) for managing DS1 interfaces. Extended functions are provided by the CA Enterprise MIB. The complete MIB for CA’s Access Navigator is in the ACCNAV.MIB file included on the CD- ROM containing this manual.

Objects are managed using “messages.” SNMP Manager operations include simple “get” and “set” messages to read and write MIB data in the Agent. The Manager can get (read) all values, but not all values can be set (changed). Table C-2lists standard Manager messages.

NetworkValet™ EMS and Valet™ software provide a graphical user interface to manage the Access Navigator MIB using simple menus, boxes, and buttons that the software translates into the appropriate SNMP messages.

Normally, the Manager polls the Agent periodically to check traffic statistics and system status. The Manager can also set object values that control device operation, such as resetting registers and enabling interfaces. The SNMP Agent can also send “trap” messages to the Manager. Trap messages are used to report when certain network events happen, such as a DS1 linkdown. When a trap event occurs, the Agent automatically sends an SNMP trap message back to the Manager, without waiting to be polled. (See SNMP Trap Reports on page C-9.)

 

Table C-2 Standard SNMP Messages

 

 

 

Message Type

 

Description

 

 

 

“get” Request

 

Returns the value of a named object. Used

 

 

to fetch performance and statistics informa-

 

 

tion and device settings.

 

 

 

“get-next” Request

 

Returns the name and value of the “next”

 

 

object. Allows manager to determine all the

 

 

names and values that a device supports.

 

 

 

“set” Request

 

Sets the named object to a specific value.

 

 

 

“trap” Message

 

Sends a trap message to the manager. Used

 

 

to notify one or more network devices that a

 

 

problem occurred.

 

 

 

C-6

August 2003

Access Navigator - Release 1.8

Page 664
Image 664
Carrier Access Access Navigator user manual Managing Networks, Table C-2 Standard Snmp Messages, Message Type Description