On Centos, I ran into the following error:
sudo snmptrap -v 2c -c read localhost '' UPS-MIB::upsTraps
MIB search path: /root/.snmp/mibs:/usr/share/snmp/mibs
Cannot find module (UPS-MIB): At line 0 in (none)
UPS-MIB::upsTraps: Unknown Object Identifier
The above error happened after
Copied UPS-MIB.txt to /usr/share/snmp/mibs
I started snmptrapd:
snmptrapd -f -Lo -Dread-config -m ALL
The version of the Net-SNMP is 5.2.x.
The same procedures work fine with Ubuntu 18.04/Net-SNMP 5.3.7. I wonder how to debug and fix the problem?
Besides the Net-SNMP version difference, on Ubuntu, I found an instruction to install mib-download-tool, and execute it after the installation of Net-SNMP, and comment out the lines beginning with min: in snmp.conf in order to fix the error of missing MIB's.
However, for the Centos, I had no need and found no such instruction, thus I have not done it yet, as there is no error message of missing MIB's.
The MIB file is downloaded from https://tools.ietf.org/rfc/rfc1628.txt renamed to UPS-MIB.txt (It seems to me that the name of the MIB file does not matter, as long as it's unique? I tried to use a different names, upsMIB.txt, rfc1628.txt, but it does not help to improve.)
I solved the problem as follows: manually copied /usr/share/snmp/mibs/ietf/UPS-MIB on an Ubuntu with Net-SNMP 5.7.3 installed to the Centos /usr/share/snmp/mibs/UPS-MIB
then restart the snmpd by the command:
service snmpd restart
then the OID of UPS-MIB becomes visible and accessible.
Maybe, the version that I downloaded from https://tools.ietf.org/rfc/rfc1628.txt is not suitable??