What is the effect of setting the security level of SNMPv3 to 'auth'?

Setting the security level of SNMPv3 to 'auth' means that packets are authenticated using either HMAC with MD5 or SHA. This authentication process ensures that the data sent between the SNMP manager and the device is verified to be valid and comes from a legitimate source. By requiring authentication, SNMPv3 helps prevent unauthorized access and ensures that any commands or information transmitted cannot be manipulated or spoofed by an attacker.

While the 'auth' security level protects against certain types of attacks, it does not encrypt the actual data being transmitted; for that, a higher security level that includes encryption would be required. This distinction is important in understanding the differing levels of security provided by SNMPv3 options.