[Kea-users] single subnet for multiple interfaces

[Joe Botha]

Hi

Using client classes seems like a good plan.

if packet comes in on eth0.1 or eth0.2 or eth0.3 - give them all IPs in 192.0.2.0/24

does this make sense?

"Dhcp4": {
    "client-classes": [
        {
            "name": "Client_foo",
            "test": "split(pkt.iface, '.', 1) == eth0",
            "option-data": [
                {
                    "name": "domain-name-servers",
                    "code": 6,
                    "space": "dhcp4",
                    "csv-format": true,
                    "data": "192.0.2.1, 192.0.2.2"
                }
            ]
        },
        ...
    ],
    "subnet4": [
        {
            "id": 1,
            "subnet": "192.0.2.0/24",
            "pools": [
                {
                    "pool": "192.0.2.10 - 192.0.2.20",
                    "client-class": "Client_foo"
                }
            ]
        },
        ...
    ],
    ...
}

-- 
Swimmingly,
 Joe

swimgeek.com/blog  +27 82 562 6167  instagram.com/joe.swimgeek
      "...all progress depends on the unreasonable man.”



> On 13 Jul 2023, at 17:40, Darren Ankney <darren.ankney at gmail.com> wrote:
> 
> Hi Joe,
> 
> In that case, shouldn't all of the DHCP traffic be present on the
> loopback?  Therefore, telling Kea to only listen on the loopback
> containing this gateway would be most appropriate?  Otherwise, you
> might have to do some class magic to assign clients to the subnet
> regardless of their interface.  You can only specify one interface per
> subnet in Kea.  I've honestly never tried this in Kea.
> 
> Thank you,
> 
> Darren Ankney
> 
> On Thu, Jul 13, 2023 at 11:33 AM Joe Botha <joe at swimgeek.com> wrote:
>> 
>> Hi
>> 
>> We look at using relays, but ISC DHCP relay is end-of-life, and it can’t add v6 PD routes - so we are looking at just installing Kea on the switch - which is why we want an IP pool shared with multiple VLAN interfaces.
>> 
>>> Does the subnet need to receive different networking/routing details
>>> depending on which VLAN it is attached to?
>> 
>> Nope, all the same gateway IP - which we will probably put on a loopback interface.
>> 
>> --
>> Swimmingly,
>> Joe
>> 
>> swimgeek.com/blog  +27 82 562 6167  instagram.com/joe.swimgeek
>>      "...all progress depends on the unreasonable man.”
>> 
>> 
>> 
>> 
>>> On 13 Jul 2023, at 17:22, Darren Ankney <darren.ankney at gmail.com> wrote:
>>> 
>>> Hi Joe,
>>> 
>>> Does the subnet need to receive different networking/routing details
>>> depending on which VLAN it is attached to?
>>> 
>>> Is the DHCP traffic relayed?
>>> 
>>> You might be able to something like:
>>> 
>>> "subnet4": [
>>> {
>>>   "id": 1,
>>>    "subnet": "192.0.2.0/24",
>>>    "relay": {
>>>       "ip-addresses": [ "198.51.100.1", "198.51.100.2" ]
>>>    }
>>> }
>>> ]
>>> 
>>> where you are specifying multiple relay ips to use for assigning from
>>> one subnet.  Take care here as the clients will all receive the same
>>> details (subnet mask, default gw etc..) so it must be confirmed that
>>> this is ok from a routing prospective.
>>> 
>>> Thank you,
>>> 
>>> Darren Ankney
>>> 
>>> On Thu, Jul 13, 2023 at 11:07 AM Joe Botha <joe at swimgeek.com> wrote:
>>>> 
>>>> Hi
>>>> 
>>>> Is there a way to configure Kea so you can share a subnet over multiple interfaces?
>>>> 
>>>> Use case is something like sharing a /24 subnet where you have a few VLAN interfaces on the server.
>>>> 
>>>> --
>>>> Swimmingly,
>>>> Joe
>>>> 
>>>> swimgeek.com/blog  +27 82 562 6167  instagram.com/joe.swimgeek
>>>>     "...all progress depends on the unreasonable man.”
>>>> 
>>>> 
>>>> 
>>>> --
>>>> ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.
>>>> 
>>>> To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
>>>> 
>>>> Kea-users mailing list
>>>> Kea-users at lists.isc.org
>>>> https://lists.isc.org/mailman/listinfo/kea-users
>> 
>> --
>> ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.
>> 
>> To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
>> 
>> Kea-users mailing list
>> Kea-users at lists.isc.org
>> https://lists.isc.org/mailman/listinfo/kea-users