Logging messages#

The logging plugin to the SNMP Proxy Forwarder lets you record pieces of passing SNMP messages to a file or to syslog. Log record format and content is fully configurable.

For more information please refer to the logger plugin documentation.

Server configuration#

Server is configured to:

listen on UDP socket at localhost
respond to queries performed over SNMPv2c
forward all queries to snmpfwd client through an unencrypted trunk connection running in client mode

#
# SNMP forwarder: Agent part configuration
#

config-version: 2
program-name: snmpfwd-server

snmp-credentials-group {
  snmp-transport-domain: 1.3.6.1.6.1.1.100
  snmp-bind-address: 127.0.0.1:1161

  snmp-engine-id: 0x0102030405070809

  snmp-community-name: public
  snmp-security-name: public
  snmp-security-model: 2
  snmp-security-level: 1

  snmp-credentials-id: snmp-credentials
}

context-group {
  snmp-context-engine-id-pattern: .*?
  snmp-context-name-pattern: .*?

  snmp-context-id: any-context
}

content-group {
  snmp-pdu-type-pattern: .*?
  snmp-pdu-oid-prefix-pattern-list: .*?

  snmp-content-id: any-content
}

peers-group {
  snmp-transport-domain: 1.3.6.1.6.1.1.100
  snmp-bind-address-pattern-list: .*?
  snmp-peer-address-pattern-list: .*?

  snmp-peer-id: 100
}

trunking-group {
  trunk-bind-address: 127.0.0.1
  trunk-peer-address: 127.0.0.1:30301
  trunk-ping-period: 60
  trunk-connection-mode: client

  trunk-id: trunk-1
}

routing-map {
  matching-snmp-context-id-list: any-context
  matching-snmp-content-id-list: any-content

  matching-snmp-credentials-id-list: snmp-credentials
  matching-snmp-peer-id-list: 100

  using-trunk-id-list: trunk-1
}

Download server configuration file.

Plugin configuration#

The logger plugin is configured at the client side to:

write key facts about passing SNMP GET request and RESPONSE PDUs into a local file
double-quote var-bindings values
autorotate log file daily
keep no more than 30 log files

#
# SNMP Proxy Forwarder: logger plugin configuration
#

[general]
# log into a file
#method: file

# log through syslog
#method: syslog

# log into main process log
#method: snmpfwd

# inhibit any logging
#method: null

# logging level: debug, info, error
#level: info

[file]
# log into this file
destination: /tmp/snmpfwd-brief.log

# use time-based file rotation
#rotation: timed

# keep up to this number of logs upon rotation
#backupcount: 30

# rotate each day
#timescale: D
#interval: 1

[syslog]
# syslog transport: udp, tcp, socket or path to syslog socket
#transport: socket

# syslog facility (see `man syslog`)
#facility: daemon

# use non-local syslog
#host: localhost

# non-default syslog port
#port: 514

[content]
# log these PDU types
#pdus: GetRequest GetNextRequest SetRequest GetBulkRequest InformRequest SNMPv2Trap Response

# log message template
#template: ${isotime} ${callflow-id} ${snmp-peer-address} ${snmp-pdu-type} ${snmp-var-binds}

# values in var-binds can be surrounded by these tokens
#parentheses: " "

Download plugin configuration file.

Client configuration#

Client is configured to:

listen on server-mode unencrypted trunk connection
process all incoming SNMP messages in the same way
run command request (and response) PDUs through the logger plugin
place inbound PDUs into SNMP v2c messages and forward them to public SNMP agent running at demo.pysnmp.com

#
# SNMP forwarder: Manager part configuration
#

config-version: 2
program-name: snmpfwd-client

peers-group {
  snmp-engine-id: 0x0102030405070809

  snmp-transport-domain: 1.3.6.1.6.1.1.1
  snmp-bind-address: 0.0.0.0:0

  # time out SNMP request in 1 second
  snmp-peer-timeout: 100
  snmp-peer-retries: 0

  snmp-community-name: public
  snmp-security-name: public
  snmp-security-model: 2
  snmp-security-level: 1

  snmp-peer-address: 104.236.166.95:161
  snmp-peer-id: snmplabs
}

trunking-group {
  trunk-bind-address: 127.0.0.1:30301
  trunk-ping-period: 60
  trunk-connection-mode: server

  trunk-id: <discover>
}

original-snmp-peer-info-group {
  orig-snmp-bind-address-pattern: .*?
  orig-snmp-context-name-pattern: .*?

  orig-snmp-pdu-type-pattern: .*?
  orig-snmp-oid-prefix-pattern: .*?

  orig-snmp-engine-id-pattern: .*?
  orig-snmp-context-engine-id-pattern: .*?

  orig-snmp-transport-domain-pattern: .*?
  orig-snmp-peer-address-pattern: .*?

  orig-snmp-security-level-pattern: .*?

  orig-snmp-security-name-pattern: .*?
  orig-snmp-security-model-pattern: .*?

  orig-snmp-peer-id: manager-1
}

server-classification-group {
  server-snmp-credentials-id-pattern: .*?
  server-snmp-context-id-pattern: .*?
  server-snmp-content-id-pattern: .*?
  server-snmp-peer-id-pattern: .*?

  server-classification-id: any-classification
}

plugin-modules-path-list: ./plugins ${plugin-dir}

plugin-group {
  plugin-module: logger
  plugin-options: config=${config-dir}/plugins/logger.conf

  plugin-id: custom-logger
}

routing-map {
  matching-trunk-id-list: trunk-1
  matching-orig-snmp-peer-id-list: manager-1
  matching-server-classification-id-list: any-classification

  using-plugin-id-list: custom-logger
  using-snmp-peer-id-list: snmplabs
}

Download client configuration file.