DHCP client moving between networks

[Glenn Satchell]

Hi Tim

You have a shared-network around the 216.xxx.46.0 and 172.16.32.0
subnets. This means when a request comes from that relay dhcpd is
allowed to allocate from either pool. As the clients are requesting a
valid address for the shared-network then it will be ACKed.

If these two networks are "on the same physical network" then a
shared-network is appropriate and you need a different way to allocate
to the new subnet and not the old one. If they are on different vlans,
then the shared-network is not appropriate and you should remove that
part of the configuration.

regards,
-glenn
--
Glenn Satchell   mailto:glenn.satchell at uniq.com.au | Miss 9: What do you
Uniq Advances Pty Ltd       http://www.uniq.com.au | do at work Dad?
PO Box 70 Paddington NSW Australia 2021            | Miss 6: He just
tel:0409-458-580     fax:02-9380-6416              | types random stuff.

>Date: Wed, 30 Sep 2009 17:50:04 -0700
>Subject: Re: DHCP client moving between networks
>From: Tim Gavin <livewire98801 at gmail.com>
>To: Users of ISC DHCP <dhcp-users at lists.isc.org>
>X-BeenThere: dhcp-users at lists.isc.org
>
>Heh, if  you guys hadn't asked for this, I wouldn't have noticed that
>I was still giving out hour-long leases on part of the network :)
>
>
>
>##########
>#VLAN 287#
>##########
>
>shared-network 287 {
>        subnet 216.xxx.46.0 netmask 255.255.255.0 {
>          range 216.xxx.46.6 216.xxx.46.254;
>          option domain-name-servers 208.xxx.220.131, 208.xxx.220.132;
>          option domain-name "mycompany.tld";
>          option routers 216.xxx.46.1;
>          option broadcast-address 216.xxx.46.255;
>          default-lease-time 43200;     #12 hours
>#         default-lease-time 3600;      #1 hour
>          max-lease-time 86400;         #24 hours
>#         max-lease-time 7200;          #2 hours
>          authoritative;
>        }
>        subnet 172.16.32.0 netmask 255.255.240.0 {
>          range 172.16.33.1 172.16.38.255;
>          option domain-name-servers 172.16.32.21, 172.16.32.22;
>          option domain-name "mycompany.tld";
>          option routers 172.16.32.1;
>          option broadcast-address 172.16.47.255;
>          default-lease-time 43200;     #12 hours
>#         default-lease-time 3600;      #1 hour
>          max-lease-time 86400;         #24 hours
>#         max-lease-time 7200;          #2 hours
>          authoritative;
>        }
>authoritative;
>}
>
>
>
>##########
>#VLAN 288#
>##########
>
>subnet 216.xxx.25.0 netmask 255.255.255.0 {
>  range 216.xxx.25.150 216.xxx.25.250;
>  option routers 216.xxx.25.1;
>  option domain-name-servers 208.xxx.220.131, 208.xxx.220.132;
>  option domain-name "mycompany.tld";
>  option broadcast-address 216.xxx.25.255;
>  default-lease-time 43200;
>  max-lease-time 86400;
>  authoritative;
>}
>
>
>
>
>
>#########
>#VLAN 703#
>##########
>
>shared-network 703 {
>        subnet 208.xxx.223.0 netmask 255.255.255.0 {
>          range 208.xxx.223.5 208.xxx.223.240;
>          option domain-name-servers 208.xxx.220.131, 208.xxx.220.132;
>          option domain-name "mycompany.tld";
>          option routers 208.xxx.223.1;
>          option broadcast-address 208.xxx.223.255;
>          default-lease-time 43200;
>          max-lease-time 86400;
>          authoritative;
>        }
>authoritative;
>}
>
>
>
>
>##########
>#VLAN 283#
>########
>
>shared-network 283 {
>        subnet 216.xxx.27.0 netmask 255.255.255.0 {
>          range 216.xxx.27.10 216.xxx.27.120;
>          option domain-name-servers 208.xxx.220.131, 208.xxx.220.132;
>          option domain-name "mycompany.tld";
>          option routers 216.xxx.27.1;
>          option broadcast-address 216.xxx.45.255;
>          default-lease-time 43200;
>          max-lease-time 86400;
>          authoritative;
>        }
>
>        subnet 208.xxx.220.192 netmask 255.255.255.224 {
>          option domain-name-servers 208.xxx.220.131, 208.xxx.220.132;
>          option domain-name "mycompany.tld";
>          option routers 208.xxx.220.193;
>          option broadcast-address 208.xxx.220.223;
>          default-lease-time 43200;
>          max-lease-time 86400;
>          authoritative;
>        }
>authoritative;
>}
>
>host marshall {
>hardware ethernet 00:11:22:33:44:55;
>fixed-address 208.xxx.220.207;
>}
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