MAC36NL - SNMP - Problem with communication over the SNMP protocol

Issue

After installing the nSnmp module on the iSMA-B-MAC36NL-family controller, adding it to the station, and configuring it correctly, the device does not respond to the sample SNMP client program.

Possible causes and solutions

Default 161 and 162 port are in use

SNMP default ports are 161 and 162. Unfortunately, the MAC36NL controller does not support using port below 1023 with few exceptions, such as HTTP, HTTPS, or Modbus TCP.

Solution

To solve the problem, use ports over 1023, for example, 1161 and 1162.

SNMP in version 3 is in use

SNMP version 3 requires the Usm user to be configured for proper communication. Today, the SNMPv3 standard is noncurrent, and the SNMPv3 RFC 3414 standard regarding the user security model has been changed.

Tridium has introduced an improved user security model to the nSnmp driver in versions 4.10u7, 413u1, and 4.14.

That is why, depending on the Niagara version installed on the MAC36 controller and if the SNMP client in use has upgrades implemented, the problem with the communication can occur or not.

Solution

To solve the problem, install Niagara in version 4.10u7 or 4.13u2 on the MAC36 controller if the SNMP client supports the new model of user security. Alternatively, install any earlier version if the SNMP client does not support the new user security model. It is also possible to upgrade the SNMP client.