[Kea-users] Lease same IP for same MAC

Sun Dec 27 20:59:51 UTC 2020

I've got a similar workflow set up but I use VMware's *dcli* module to
create my instance, which also allows me to explicitly set the MAC address
(and thus force reservations).

Looking at the Packer docs (
https://www.packer.io/docs/builders/vsphere-iso.html) you may be able to do
this as well by defining the Network Adapter before starting the instance,
and use a reservation in Kea to fix the IP.

hth,
Klaus

On Sun, Dec 27, 2020 at 10:40 AM Roland Berger <roland.berger at exasoft.ch>
wrote:

> 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,
>
>
>
> [image: 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> <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
>
>
>
> --
> Sent from: http://kea-users.7364.n8.nabble.com/
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