SNMPv2c uses community strings as the mechanism for authentication. The community string is a shared secret between the SNMP agent and SNMP manager that is used to authenticate and authorize SNMP requests.
There are two types of community strings in SNMPv2c:
1. Read-only community string: this community string allows the SNMP manager to read SNMP data from the SNMP agent.
1. Read-write community string: this community string allows the SNMP manager to both read and write SNMP data to the SNMP agent.
When an SNMP request is made, the community string is included in the request packet. The SNMP agent checks the community string to verify that the request is authorized. If the community string matches the one configured on the SNMP agent, the request is processed. If not, the request is rejected.
It is important to note that SNMPv2c provides very weak security, and the community strings can easily be intercepted and exposed by attackers. Thus, it is recommended to use SNMPv3, which provides more robust security features such as encryption and authentication via digital certificates.
