OS6860(E)_AOS_8.1.1.R01_Switch_Management_Guide

SNMP Overview
Using SNMP
The community string security standard offers minimal security and is generally insufficient for networks
where the need for security is high. Although SNMPv1 lacks bulk message retrieval capabilities and security
features, it is widely used and is a de facto standard in the Internet environment.
SNMPv2
SNMPv2 is a later version of the SNMP protocol. It uses the same Get, Set, GetNext, and Trap operations
as SNMPv1 and supports the same community-based security standard. SNMPv1 is incompatible with
SNMPv2 in certain applications due to the following enhancements:
• Management Information Structure
SNMPv2 includes new macros for defining object groups, traps compliance characteristics, and
capability characteristics.
• Protocol Operations
SNMPv3
SNMPv2 has two new PDUs not supported by SNMPv1. The GetBulkRequest PDU enables the
manager to retrieve large blocks of data efficiently. In particular, it is well suited to retrieving multiple
rows in a table. The InformRequest PDU enables one manager to send trap information to another
manager.
SNMPv3 supports the View-Based Access Control Model (VACM) and User-Based Security Model
(USM) security models along with these added security features:
• Message integrity—Ensuring that a packet has not been tampered with in transit.
• Time Frame Protection—Limiting requests to specified time frames. The user can specify a time frame
so that any PDU bearing an out of date timestamp will be ignored.
• Encryption—Scrambling the contents of a packet to prevent it from being learned by an unauthorized
source.
• Authentication—Determining that the message is from a valid source holding the correct privileges.
page 9-8 OmniSwitch AOS Release 8 Switch Management Guide May 2014