SNMP/SNMPTRAP input with filter and output to CSV

Elastic Stack Logstash
2

If I use that snmp input I get

  "iso.org.dod.internet.mgmt.mib-2.system.sysUpTime.sysUpTimeInstance" => 202330,
"iso.org.dod.internet.mgmt.mib-2.interfaces.ifTable.ifEntry.ifDescr.2" => "error: no such instance currently exists at this OID",

Personally I would adjust that using 'oid_root_skip => 6' to get the easier to read

  "system.sysUpTime.sysUpTimeInstance" => 198404,
"interfaces.ifTable.ifEntry.ifDescr.0" => "error: no such instance currently exists at this OID",

Unfortunately this is a terrible match for a csv filter. I would suggest something like

output { file { path => "/some/path/snmp.txt" codec => json_lines } }

Not sure what you are looking to do with grok. Are there specific fields you need to parse?