how to know how many ip are assigned

[Simon Hobson]

Luc T. wrote:

>how can I know how many IPs in a subnet have been assigned? by 
>looking at the dhcpd.leases file? do I need to look at the 
>dhcpd.leases~ file?

Yes. But there are already a couple of scripts that will do it for 
you - try the mail archives. IIRC there's at least one stand alone 
script, and at least one cgi script so you can find out remotely with 
your web browser.

>   when an assigned IP is released by the client, will dhcpd delete 
>the entry in the dhcpd.lease file? I mean if I can conclude that an 
>IP is available if the IP can not be found in the dhcp.leases file.

Two different questions there. To the first, no it does not delete 
the record of a lease - it is left so as to allow the same address to 
be allocated should the client return to the network. Expired leases 
should be identified as such though.

To the second, yes - with the proviso that you have to parse the 
config file to know what addresses are included in pools before you 
can work out which of them are free.