[Kea-users] Lease same IP for same MAC

[Roland Berger]

Hi John

Thanks. Packer is a tool to automatically bring up and configure a 
virtual machine for the first time. It is like installing, for example 
an ubuntu, machine from an iso image: The installer runs and after 
completion the new machine makes a reboot and you can continue to 
configure the new machine. So, I do not know the MAC address in advance 
to make a reservation.

The challenge I think I face is to make sure that the IP address after 
the reboot is the same like during first power up when the os installer 
is running.
I think I have to create a configuration where kea issues the same IP 
for the above scenario. I tried this to make sure that the MAC address 
and the hostname are the same. I also configured networking of the new 
machine to send 'dhcp-identifier: mac'. But that is obviously not enough.

Thanks to your answer I see the following things I can try. But may be 
you have even a better, simpler idea.
- Create a MAC address by hand and make a reservation
- Try to play around with the lease time for the first DHCP request.
- Use static IP but in this case I don't want to do that if I can avoid it.
- Configure kea to use only "host-reservation-identifiers": 
["hw-address"] but not sure if this would help.

Best Roland

192.168.178.*251*,00:50:56:92:07:82,01:00:50:56:92:07:82,0   ,1609062019,1,1,1,ubuntu-server,0,
192.168.178.*252*,00:50:56:92:07:82,01:00:50:56:92:07:82,4000,1609066573,1,1,1,ubuntu-server,0,



www.exasoft.ch <http://www.exasoft.ch>
On 12/27/20 12:06 PM, Gibbins, John (IM&T, Black Mountain) wrote:
> Hi Roland,
>
> If the client does not request the same IP as it had before you probably need to assign a fixed IP to the device.
>
> I'm assuming you have a config which includes your subnet.  Something like:
> ...
>      "subnet4": [
>        {
>          "subnet": "192.168.178.0/24",
>          ...
>        }
>      ]
> ...
>
> To ensure that you always get the same IP you need to create a reservation which maps the MAC to the desired IP.  Such as:
> ...
>      "subnet4": [
>        {
>          "subnet": "192.168.178.0/24",
>          ...
>          "reservations": [
>            {
>              "hw-address": "00:50:56:92:07:82",
>              "ip-address": "192.168.178.251"
>            }
>          ]
>        }
>      ]
> ...
>
> You may want to check out the "reservation-mode" attribute if you have both pools and reservations on the same subnet.
>
> Regards
> johng
> -----Original Message-----
> From: Kea-users <kea-users-bounces at lists.isc.org> On Behalf Of rondal
> Sent: Sunday, 27 December 2020 9:23 PM
> To: kea-users at lists.isc.org
> Subject: [Kea-users] Lease same IP for same MAC
>
> Hi, I try to deploy an ubuntu server to vsphere with packer. After
> installation has finished the machine reboots an gets an other IP address.
> Packer can not complete its work because it is still trying to connect to
> the old ip address.
>
>  From the kea log I see the following:
>
> 192.168.178.*251*,00:50:56:92:07:82,01:00:50:56:92:07:82,0
> ,1609062019,1,1,1,ubuntu-server,0,
> 192.168.178.*252*,00:50:56:92:07:82,01:00:50:56:92:07:82,4000,1609066573,1,1,1,ubuntu-server,0,
>
> In the client I configure networking (netplan) with dhcp-identifier: mac
>
> - Any ideas how I can tell kea to lease the same ip, in this case *.251,
> again?
>
>
> Best Roland
>
>
>
> --
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