DHCP

> 2. Secondly, I am also wondering if a "pool" of MAC addresses can be

> setup so that only MAC's listed can be given an IP, but is random
within
> a range of valid IP addresses.

This one can at least.

subnet 10.4.0.0 netmask 255.255.0.0 {
authoritive;
option subnet-mask 255.255.0.0;
option broadcast-address 10.0.255.255;
pool {
range 10.4.254.1 10.4.254.254;
option routers 10.4.0.1;
option domain-name-servers 10.4.0.7;
default-lease-time 120;
max-lease-time 120;
allow unknown clients;
}
pool {
range 10.4.1.1 10.4.5.254;
option routers 10.4.0.1;
option domain-name-servers 10.0.0.17, 10.0.0.23;
default-lease-time 1209600;
max-lease-time 1209600;
deny unknown clients;
}
}

host wwebster-1 { hardware ethernet 00:D0:09:28:05:56 ; ddns-hostname
wwebster-1;}
host cclark-1 { hardware ethernet 00:A0:D2:1A:7C:A5 ; ddns-hostname
cclark-1;}

These computers will be given IP's out of the second pool of addresses.
The first pool is not needed for you most likely (it is part of a
captive portal system).

Hello all,

I have two questions regard DHCP:

1. Can I have DHCP execute a script for each lease it gives? What I
would like to do is for everytime an IP is assigned, I would like it to
execute a script which will set bandwidth restrictions on that IP (two
arguments of that script would have to be MAC address and IP address).
Also, is there a way of running a script upon termination of a lease (do
the opposite of the first script).

2. Secondly, I am also wondering if a "pool" of MAC addresses can be
setup so that only MAC's listed can be given an IP, but is random within
a range of valid IP addresses.

Thanks in advance.
Kevin Brown

Kevin Brown <-NOSPAM-itismekevinb-NOSPAM-@hotmail.com> wrote:
> 1. Can I have DHCP execute a script for each lease it gives? What I
> would like to do is for everytime an IP is assigned, I would like it to
> execute a script which will set bandwidth restrictions on that IP (two
> arguments of that script would have to be MAC address and IP address).
> Also, is there a way of running a script upon termination of a lease (do
> the opposite of the first script).

You script may monitor /var/log/messages for records written on behalf
of DHCP daemon every time client requests/reconfirms/releases IP address,
and then do whatever you need (reconfigure iptables, or router).

--
andrei

Kevin Brown <-NOSPAM-itismekevinb-NOSPAM-@hotmail.com> wrote:
> 1. Can I have DHCP execute a script for each lease it gives? What I
> would like to do is for everytime an IP is assigned, I would like it to
> execute a script which will set bandwidth restrictions on that IP (two
> arguments of that script would have to be MAC address and IP address).
> Also, is there a way of running a script upon termination of a lease (do
> the opposite of the first script).
On a quick review, I can't find the man page/reference where I found this
before, but for every new DHCP lease (my system uses dhclient), the script
/etc/dhclient-exit-hooks is executed. I can't recall if I set this up in
a config file or it's executed if it exists. I use this script to update
/etc/hosts when I get a new IP address. When called, environment variables
contain various details about the event.
--
... Tim Rhodes ........................ http://rhodes.cc.vt.edu/~rhodes ..
... NIS-Systems Support, Virginia Tech .............. Tim.Rhodes@vt.edu ..

Tim Rhodes wrote:
> Kevin Brown <-NOSPAM-itismekevinb-NOSPAM-@hotmail.com> wrote:
> > 1. Can I have DHCP execute a script for each lease it gives? What
I
> > would like to do is for everytime an IP is assigned, I would like
it to
> > execute a script which will set bandwidth restrictions on that IP
(two
> > arguments of that script would have to be MAC address and IP
address).
> > Also, is there a way of running a script upon termination of a
lease (do
> > the opposite of the first script).
> On a quick review, I can't find the man page/reference where I found
this
> before, but for every new DHCP lease (my system uses dhclient), the
script
> /etc/dhclient-exit-hooks is executed. I can't recall if I set this
up in
> a config file or it's executed if it exists. I use this script to
update
> /etc/hosts when I get a new IP address. When called, environment
variables
> contain various details about the event.

/sbin/dhclient-script ?

On 3 Feb 2005 16:29:05 -0800, prg wrote:
>
> /sbin/dhclient-script ?

That is the script which calls /etc/dhclient-exit-hooks if it exists.
/sbin/dhclient-script should not be modifed.
User code goes in /etc/dhclient-exit-hooks.

Bit Twister wrote:
> On 3 Feb 2005 16:29:05 -0800, prg wrote:
> >
> > /sbin/dhclient-script ?
>
> That is the script which calls /etc/dhclient-exit-hooks if it exists.
> /sbin/dhclient-script should not be modifed.
> User code goes in /etc/dhclient-exit-hooks.

"...the script which calls /etc/dhclient-exit-hooks" is what he could
not find, so I told him how to find where /etc/dhclient-exit-hooks
(exit_with_hooks) is called. No? That's the whole point of
exit_with_hooks. No?

But I may have misunderstood -- not the first time ;)

regards,
prg
email above disabled

On 3 Feb 2005 17:08:37 -0800, prg wrote:
>
> But I may have misunderstood -- not the first time ;)

Tim had indicated he could not remember how he knew about dhclient-exit-hooks

man dhclient-script talks about it.

I misunderstood your response. I assumed you were suggesting the user
modify /sbin/dhclient-script. O:-)

Bit Twister wrote:
> On 3 Feb 2005 17:08:37 -0800, prg wrote:
> >
> > But I may have misunderstood -- not the first time ;)
>
> Tim had indicated he could not remember how he knew about
dhclient-exit-hooks
>
> man dhclient-script talks about it.
>
> I misunderstood your response. I assumed you were suggesting the user
> modify /sbin/dhclient-script. O:-)

And so might someone else without you prodding me into a clarification.

All bases covered. Is that teamwork, or what?

prg