Communicating With The Snmp Engine; Table 18: Snmpengineid Structure Object - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - SYSTEM BASICS CONFIGURATION GUIDE 2010-10-04 Configuration Manual

JunosE 11.3.x System Basics Configuration Guide

Communicating with the SNMP Engine

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each virtual router agent to address any network security issues. To disable proxy on an
agent (router), you must use SNMP or the CLI snmp-server proxy disable command.
NOTE: Disabling the proxy function on a particular virtual router disables the
use of proxy through that virtual router. You can, however, use the proxy
function to access a proxy-disabled virtual router through another virtual
router that does have the proxy function enabled.
The SNMP engine performs the following tasks for SNMPv3:
Sends and receives messages.
Prepares messages and extracts data from messages.
Authenticates, encrypts, and decrypts messages.
Determines whether access to a managed task is allowed.
Each SNMP engine has an SnmpEngine ID, a hexadecimal number 15 octets long. Table
18 on page 144 shows the structure of the SnmpEngine ID.

Table 18: SnmpEngineID Structure Object

Octet
Assignment Description
1 – 4 E Series router SNMP management private enterprise number
5 Indicates that octets 6–15 contain information determined by the E Series
router
6 – 11 The MAC address for the device. For E120 and E320 routers, the MAC
address is a unique ID based on chassis ID.
12 – 15 The 32-bit (4 octet) router index (or routerUID)
Request protocol data units (PDUs) for the SNMP engine must contain the corresponding
contextEngine ID and contextName for the SNMP engine. When the system receives a
PDU, it examines the contextEngine ID and contextName, and forwards the request to
the corresponding virtual router.
The contextEngine ID is the same as the SnmpEngine ID.
The contextName is an internally derived ASCII string associated with the router. It has
the format routerN, where N is a number (with no leading zeros) in the range 1–16777215,
corresponding to the least significant 24 bits of the 32-bit router index (or router UID).
You can obtain the contextName for a specific router through the Juniper-ROUTER-MIB
from the juniRouterContextName object in the juniRouterTable, which is indexed by
the 32-bit router index (juniRouterIndex).
Copyright © 2010, Juniper Networks, Inc.