connections

check_connections

Checks the number of tcp connections.

Implementation

Windows	Linux	FreeBSD	MacOSX
✅	✅		✅

Examples

Default Check

check_connections
OK - total connections 60

Check only ipv6 connections:

check_connections inet=ipv6
OK - total ipv6 connections 13

Example using NRPE and Naemon

Naemon Config

define command{
    command_name         check_nrpe
    command_line         $USER1$/check_nrpe -H $HOSTADDRESS$ -n -c $ARG1$ -a $ARG2$
}

define service {
    host_name            testhost
    service_description  check_connections
    use                  generic-service
    check_command        check_nrpe!check_connections!'warn=total > 500' 'crit=total > 1500'
}

Argument Defaults

Argument	Default Value
filter	inet=total
warning	total > 1000
critical	total > 2000
empty-state	0 (OK)
empty-syntax
top-syntax	%(status) - ${list}
ok-syntax
detail-syntax	total ${prefix}connections: ${total}

Check Specific Arguments

Argument	Description
inet	Use specific address family only. Can be: total, any, ipv4 or ipv6

Attributes

Filter Keywords

these can be used in filters and thresholds (along with the default attributes):

Attribute	Description
inet	address family, can be total (sum of any), all (any+total), any (v4+v6), inet4 or inet6
prefix	address family as prefix, will be empty, inet4 or inet6
total	total number of connections
established	total number of connections of type: established
syn_sent	total number of connections of type: syn_sent
syn_recv	total number of connections of type: syn_recv
fin_wait1	total number of connections of type: fin_wait1
fin_wait2	total number of connections of type: fin_wait2
time_wait	total number of connections of type: time_wait
close	total number of connections of type: close
close_wait	total number of connections of type: close_wait
last_ack	total number of connections of type: last_ack
listen	total number of connections of type: listen
closing	total number of connections of type: closing
new_syn_recv	total number of connections of type: new_syn_recv