SNMP Version 1, 2c and 3

Post date: Aug 30, 2013 1:4:29 PM

DD supports three versions of the SNMP protocol:

SNMP Version 1: The oldest and most basic version of SNMP

Pros: Supported by most devices that are SNMP compatible; simple to set up

Cons: Limited security as it only uses a simple password (“community string”) and data is sent in clear text (unencrypted); should only be used inside LANs behind firewalls, not in WANs; only supports 32bit counters which is not enough for bandwidth monitoring with high loads of some gigabits/second

SNMP Version 2c: Adds 64 bit counters

Pros: Supports 64 bit counters to monitor bandwidth usage in networks with gigabits/second loads

Cons: Limited security (same situation as with SNMP V1)

SNMP Version 3: Adds authentication and encryption

Pros: Offers user accounts and authentication for multiple users and optional encryption of the data packets, which makes it much more secure; plus all advantages of Version 2c

Cons: none

It is important to know that if you select an SNMP version which is not supported by the server or device that you want to monitor you will receive an error message. Unfortunately most of the time these error messages are not explicitly telling you about the incorrect SNMP version (they say only something like “cannot connect” or similar). The same situation exists if community string, usernames and passwords are incorrect.