This plugin uses the bulk-get mode of SNMPv2 by default - pass it the option -m NONBULK to work with SNMPv1. Support for SNMPv3 with and without privacy is included.
64 bit counters will be used if they are supported by the device.
In order to compile this plugin you need the
NET SNMP Development package
libsnmp-dev for Debian) as well as
autoconf and the standard compilation tools.
Example for Debian:
apt-get update apt-get -y install git build-essential libsnmp-dev
Download and extract the tarball from https://github.com/NETWAYS/check_interfaces/releases
Running "make" should successfully compile the plugin, and "make install" will install them under the configured path.
make make install
(see also check_interface --help)
check_interface -c public -h 192.168.0.1 -r 'FastEth' -p '$SERVICEPERFDATA$' -t $LASTSERVICECHECK$ -a Options; -h address of device -c|--community community (default public) -r|--regex interface list regexp Regex to match interfaces (important, this is a Regular Expression not a simple wildcard string, see below) -e|--errors number of in errors (CRC errors for cisco) to consider a warning (default 50) Only warn if errors increase by more than this amount between checks -f|--out-errors number of out errors (collisions for cisco) to consider a warning Defaults to the same value as for errors -p|--perfdata last check perfdata Performance data from previous check (used to calculate traffic) -P|--prefix prefix interface names with this label -t|--lastcheck last checktime (unixtime) Last service check time in unixtime (also used to calculate traffic) -b|--bandwidth bandwidth warn level in % -s|--speed override speed detection with this value (bits per sec) -x|--trim cut this number of characters from the start of interface descriptions Useful for nortel switches -j|--auth-proto SNMPv3 Auth Protocol (SHA|MD5) -J|--auth-phrase SNMPv3 Auth Phrase -k|--priv-proto SNMPv3 Privacy Protocol (AES|DES) (optional) -K|--priv-phrase SNMPv3 Privacy Phrase -u|--user SNMPv3 User -d|--down-is-ok disables critical alerts for down interfaces i.e do not consider a down interface to be critical -a|--aliases retrieves the interface description This alias does not always deliver useful information -A|--match-aliases also test the Alias against the Regexes -D|--debug-print list administrative down interfaces in perfdata -N|--if-names use ifName instead of ifDescr --timeout sets the SNMP timeout (in ms) -m|--mode special operating mode (default,cisco,nonbulk,bintec) Workarounds for various hardware
default use SNMPv2 bulk-gets to retrieve the interface list (recommended for devices with many interfaces) cisco retrieve CRC errors and collisions instead of in errors and out errors bintec work with non-RFC Bintec devices nonbulk use a traditional tree-walk and SNMPv1 instead of bulk-gets (less efficient, but works with most devices)
The plugin will query the uptime of the device and compensate for counter overflows. Note however that a 1Gbit interface with a 32 bit counter will overflow every 34 seconds if the interface is operating at full capacity - in this case you will need to query the device at least once a minute. With 64 bit counters these problems go away.
Also be aware that the counter values themselves are passed unaltered in the performance data field - if you graph the data then the grapher also needs to be overflow aware.
Large Plugin Output
Be aware that this plugin may generate large outputs. Your version of Nagios / Icinga may cut off the output and cause you problems with various graphing tools; for best results restrict the list of interfaces using the -r option
The following patterns can be used to match strings
. anything ^ beginning of string $ end of string (WARNING: you need to use $$ in a Nagios configuration file!) (abc|def) either abc or def [0-9a-z] a range * the previous pattern multiple times
Eth match any strings containing "Eth" ^FastEth match any strings beginning with "FastEth" Eth(0|2)$ match Eth0 or Eth2 Eth(0|2) as above but would also match Eth20, Eth21, Eth22 etc
If unsure of a pattern, you should test it on the command line thus;
check_interface -c public -h 192.168.0.1 -r 'Eth(0|2)$'
Docker Build Environment
You can use docker for a development environment.
docker build -t check_interfaces . docker run --rm check_interfaces -c public -h sw1
docker build -t check_interfaces . docker create --name="check_sw1" check_interfaces -c public -h sw1 docker start -a check_sw1
Create a debug build
docker build --build-arg target=debug -t check_interfaces .