Hi Joyce,Try debugging on the command line from the Observium host:snmpwalk -v2c -c <your_snmpv2_community> 172.30.2.21This should pull a lot of text.If this command does not succeed, make sure you can reach your target on port 161/udp (check your firewalls).If snmpwalk returns content, try adding the node through the command line:/opt/observium/add_device.php 172.30.2.21 <your_snmpv2_community>That will likely tell you what's wrong.HTH,Ahmed.Le mer. 14 juill. 2021, à 10 h 39, Njoroge, Joyce (Stadt Ulm) via observium <observium@observium.org> a écrit :Hallo,I am having a problem adding a few of my devices to the Observium Server. I use the same parameters for the other devices but with the few that couldn't be added, I am getting the following message.I have tried to change SNMP authentication using different protocol versions but I still get an error message.Obsevium version is Observium CE 20.9.10731.I will appreciate your help.Regards,Joyce_______________________________________________observium mailing list--Ahmed RahalAdministrateur de Systèmes / Systems AdministratorA: 550, avenueBeaumont,bureau320,Montréal (Québec)H3N 1V1Twitter: @fibrenoire_______________________________________________observium mailing listobservium@observium.orghttp://postman.memetic.org/cgi-bin/mailman/listinfo/observium