3mao / snmp

A simple SNMP poller

SNMP Poller

This program periodically polls a set of SNMP agents for the values of certain OIDs. The responses are logged to a file or database.

Current limitations

The results are printed to standard output, and not logged to a database. The first database to be supported will be someting like SQLite.

There's a seeming bug where the first two requests are sent in quick succession, before the specified delay starts being used.

Only ASN.1 values of type string, integer, and null, are supported. Responses containing other values can't be parsed properly. General ASN.1 values should be supported.

The polling isn't especially efficient: no priority queues, and no batching of requests to the same host. Additionally, host name and port are used each time a request is sent, rather than a cached sockaddr object.

Command line

poller [options]

Options include:

-v            verbose mode
-p PORT       port to listen for replies on
-c FILENAME   config file to use

The list of hosts and OIDs to poll is read from the config file, which defaults to poller.conf. If this file cannot be read, the poller will act as if an empty file is specified.

The poller will reread the config file when it receives a SIGQUIT signal.

Configuration file

The configuration file is a plain text file, with fields separated by white space. Each line is of the form:

hostname[:port]    oid    frequency

Hostname is a host name or address; port is optional and defaults to 161. OID is an OID in numeric form. Frequency is a positive value and represents the delay in seconds between successive requests for that OID from that host.

Text after the # character is treated as a comment, and blank lines are ignored.

See sample.conf for an example configuration file.