SNMP Community String

Definition for SNMP : 

Simple Network Management Protocol (SNMP) is used in network management systems in order to manage your network devices. 
SNMP exposes management data in the form of variables on the managed systems, which describe the system configuration. These variables can then be queried (and sometimes set) by managing applications (in our case SysAid). 

SNMP Community Strings 

An SNMP community string is a text string that acts as a password. It is used to authenticate messages that are sent between the management station and the device (the SNMP agent). The community string is included in every packet that is transmitted between the SNMP manager and the SNMP agent. 

In order for the management station to be able to properly discover and manage devices, the following conditions need to occur: 
- The device supports SNMP and it is enabled. 
- The community string sent in the scan matches the community string on the device. - Default string for read-only is usually "public" 
- The SNMP protocol is not blocked by a firewall, in this case you can use SysAid remote discovery service and install it on your remote networks. 
- There is a read-only and a read-write mode and each has it's own community string. 

If community strings do not match, either modify the community string at the device so that it is the string that the management station expects, or modify the management station so that it uses the device's community strings. 

 

Note: SNMP Community strings are used only by devices which support SNMPv1 and SNMPv2c protocol. SNMPv3 uses username/password authentication, along with an encryption key.

 

By convention, most SNMPv1-v2c equipment ships from the factory with a read-only community string set to "public". It is standard practice for network managers to change all the community strings to customized values in the device setup.