You just set up Net SNMP (snmpd), you configured it correctly, you started it and still don’t get any SNMP thing from the outside ? Just local snmpwalk gives some output ?

I lost pretty much time on it. I should have checked the file /etc/default/snmpd

It has a line :

SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid 127.0.0.1'

See the IP 127.0.0.1 ?! Just erase it if you want to give full access or adjust it to your local network.

That’s it !