How to query for available / used ip

Dmitry Vayntrub dmitry at sfsu.edu
Sat Jun 20 16:23:07 UTC 2015


You might also look at dhcpd-pools
http://dhcpd-pools.sourceforge.net/

It is really fast (written in C ), and the output is easy to parse, as well as present as a web page if you would like to.
Here is an example of the text mode output:
[root at ns1 dhcp]# dhcpd-pools
Ranges:
shared net name     	first ip          	 last ip          	  max   cur    percent  touch   t+c  t+c perc     bu  bu perc
sfs-wifi-dhcp-10_143_010.143.0.16          - 10.143.15.254     4079    16      0.392    860   876    21.476   2037   49.939
sfs-wifi-dhcp-10_143_1610.143.16.16     - 10.143.31.254     4079    17      0.417    934   951    23.315   2034   49.865
sfs-wifi-dhcp-10_143_3210.143.32.16     - 10.143.47.254     4079    18      0.441    830   848    20.789   2033   49.841
sfs-wifi-dhcp-10_143_4810.143.48.16     - 10.143.63.254     4079    21      0.515    934   955    23.413   2034   49.865
sfs-wifi-dhcp-10_143_6410.143.64.16     - 10.143.79.254     4079    27      0.662    876   903    22.138   2031   49.792
sfs-wifi-dhcp-10_143_8010.143.80.16     - 10.143.95.254     4079    17      0.417    906   923    22.628   2038   49.963
sfs-wifi-dhcp-10_143_9610.143.96.16     - 10.143.111.254    4079    17      0.417    922   939    23.020   2037   49.939
sfs-wifi-dhcp-10_143_11210.143.112.16    - 10.143.127.254    4079    17      0.417    922   939    23.020   1578   38.686
sfs-wifi-dhcp-10_143_12810.143.128.16    - 10.143.143.254    4079    17      0.417    923   940    23.045      0    0.000
sfs-wifi-dhcp-10_143_14410.143.144.16    - 10.143.159.254    4079    22      0.539    944   966    23.682      0    0.000
sfs-wifi-dhcp-10_143_16010.143.160.16    - 10.143.175.254    4079    19      0.466    910   929    22.775      0    0.000
sfs-wifi-dhcp-10_143_17610.143.176.16    - 10.143.191.254    4079    23      0.564    930   953    23.364      0    0.000
sfs-wifi-dhcp-10_143_19210.143.192.16    - 10.143.207.254    4079    20      0.490    888   908    22.260      0    0.000
sfs-wifi-dhcp-10_143_20810.143.208.16    - 10.143.223.254    4079    16      0.392    883   899    22.040      0    0.000
sfs-wifi-dhcp-10_143_22410.143.224.16    - 10.143.239.254    4079    18      0.441   1085  1103    27.041      0    0.000
sfs-wifi-dhcp-10_143_24010.143.240.16    - 10.143.255.254    4079    18      0.441    882   900    22.064      0    0.000

Shared networks:
name                   max   cur     percent  touch    t+c  t+c perc     bu  bu perc
sfs-wifi-dhcp-10_143_0  4079    16      0.392     860    876    21.476   2037   49.939
sfs-wifi-dhcp-10_143_16  4079    17      0.417     934    951    23.315   2034   49.865
sfs-wifi-dhcp-10_143_32  4079    18      0.441     830    848    20.789   2033   49.841
sfs-wifi-dhcp-10_143_48  4079    21      0.515     934    955    23.413   2034   49.865
sfs-wifi-dhcp-10_143_64  4079    27      0.662     876    903    22.138   2031   49.792
sfs-wifi-dhcp-10_143_80  4079    17      0.417     906    923    22.628   2038   49.963
sfs-wifi-dhcp-10_143_96  4079    17      0.417     922    939    23.020   2037   49.939
sfs-wifi-dhcp-10_143_112  4079    17      0.417     922    939    23.020   1578   38.686
sfs-wifi-dhcp-10_143_128  4079    17      0.417     923    940    23.045      0    0.000
sfs-wifi-dhcp-10_143_144  4079    22      0.539     944    966    23.682      0    0.000
sfs-wifi-dhcp-10_143_160  4079    19      0.466     910    929    22.775      0    0.000
sfs-wifi-dhcp-10_143_176  4079    23      0.564     930    953    23.364      0    0.000
sfs-wifi-dhcp-10_143_192  4079    20      0.490     888    908    22.260      0    0.000
sfs-wifi-dhcp-10_143_208  4079    16      0.392     883    899    22.040      0    0.000
sfs-wifi-dhcp-10_143_224  4079    18      0.441    1085   1103    27.041      0    0.000
sfs-wifi-dhcp-10_143_240  4079    18      0.441     882    900    22.064      0    0.000

[root at ns1 dhcp]# dhcpd-pools -help
Usage: dhcpd-pools [OPTIONS]
This is ISC dhcpd pools usage analyzer.

  -c --config   file    path to the dhcpd.conf file
  -l --leases   file    path to the dhcpd.leases file
  -f --format   [thc]   output format
                          t for text
                          h for html table
                          H for full html page
                          c for comma separated values
  -s --sort [nimcptTe]  sort ranges by
                          n name
                          i IP
                          m maxium
                          c current
                          p percent
                          t touched
                          T t+c
                          e t+c perc
  -r --reverse          reverse order sort
  -o --output   file    output into a file
  -L --limit    nr      output limit mask 77 - 00
  -v --version          version information
  -h --help             this screen

Report bugs to <kerolasa at iki.fi>

Thanks,
Dmitry Vayntrub
Systems Coordinator
Information Technology Services
San Francisco State University
(415)338-1909

-----Original Message-----
From: dhcp-users-bounces at lists.isc.org [mailto:dhcp-users-bounces at lists.isc.org] On Behalf Of Simon Hobson
Sent: Saturday, June 20, 2015 5:07 AM
To: Users of ISC DHCP
Subject: Re: How to query for available / used ip

Leandro <ingrogger at gmail.com> wrote:

> Hello Guys , I would like to plot the function of my dhcpd server on cacti graph.
> I want to know ir is there any recommended way to ask a running dhcp server how many ips were granted and how many are available ?

Check out dhcp-pool
As well as a command line tool, it has a munin plugin component. In principle it shouldn't be too hard to get it to update an RRD but I haven't got that far yet. As a command line tool it will give you information like this :

Subnet 192.168.7.0/24
--------------------------------------------------

  1. Pool "WiFi":

     Monitoring:      ON
     Warning limit:   75%
     Critical limit:  90%
     Active leases:   22/91 (24.2%)

While the Munin plugin will give you output like this :

$ dhcpd-munin_192.168.7.0_24_1
active.value 22
warning.value 68.2
critical.value 81.9
max.value 91

I figure the latter should be parseable into something that can be fed into Nagios and Cacti

_______________________________________________
dhcp-users mailing list
dhcp-users at lists.isc.org
https://lists.isc.org/mailman/listinfo/dhcp-users


More information about the dhcp-users mailing list