Debugging output
Net-SNMP applications and the agent support run-time selectable debugging output. The -D flag can be used to select tokens to display at runtime with a comma separated list. For example -Dtls,ssl,snmpd will display every debugging statement registered with the prefixes of "tls", "ssl" and "snmpd". This will include longer prefixes too such as "snmpd/main" and "sslctx_client" for example.
Command line options
Options for using -D for DEBUG output
-D token[,token[,token]...]
To see every possible output use
-D all
The token are not predefined but defined through usage.
DEBUGMSG(( token, format, ...))
To find all existing tokens try
cd net-snmp-<Version> find . -name "*.c" | xargs grep "DEBUGMSG.*\"" | sed 's/^.*((//;s/,.*$//' | sort -u | grep "^\""
for version 5.4.2.1 this returns 1589 tokens.
Some of these tokens will be found but not be used because they are inside a multiline comment.
Configuration files
Note that if you want to turn on debugging via the config file, but *only* for the agent (rather than all SNMP commands), then you'd need a block something like
[snmp] doDebugging 1 debugTokens this,that,theother
in your snmpd.conf file (the leading [snmp] token indicates it's actually going to be directives from the main snmp.conf file; use "[snmpd]" to switch back to snmpd.conf tokens after that if you need to.)