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I have a problem with our fairly new kea-dhcp setup. We have a bunch of different VLANs in use for which we want to give out DHCP-Adresses. For this purpose we use a little APU-box which serves our kea-dhcp4. This APU-box has on port on which all the different VLANs are tagged. I then setup the config, so I give out different IP-Adress-Pools for each VLAN. This is how I configured the different subnets:

{
    "subnet": "10.14.70.0/24",

    "interface": "enp3s0.70",

    "pools": [
            {
                     "pool": "10.14.70.100-10.14.70.199"
            }
    ],

    "option-data": [
            {
                    "name": "routers",
                    "data": "10.14.70.254"
            }
    ],

    "reservations": [
            {
                    "hw-address": "xx:xx:xx:xx:xx:xx",
                    "ip-address": "10.14.70.200"
            },
            {
                    "hw-address": "yy:yy:yy:yy:yy:yy",
                    "ip-address": "10.14.70.11"
            }
    ]


}

This works and I am happy with the results.
The problem happens when I put my Laptop from one VLAN into another. KEA does not seem to check which VLAN I am connected to when it already knows my MAC-Adress. If I switch from VLAN 70 to 71, instead of getting a fresh IP form the VLAN-71 subnet, I still get my old IP from the 70 subnet. This leads to me not being able to connect to the network unless I manually release my IP and request a new one.

Is there some configuration-option I can enable, so KEA always checks the interface from which the request originates? Or is there some other way around this issue?

Thank you

paddex
  • 1
  • If manually renewing the DHCP lease works, then the DHCP server is functioning as it should. You need to manually renew the DHCP lease, because DHCP leases last for a certain amount of time, the client won't renew the lease (i.e. contact the DHCP server) until it needs to based on the time. Your assumption that *KEA does not seem to check which VLAN I am connected to* is therefore incorrect, since the client isn't actually contacting the DHCP server until it needs to renew the IP address – Jaromanda X Aug 27 '23 at 23:27
  • To add to @JaromandaX comments, you are probably switching vlans digitally (or some other method I am not aware of). If you were to switch vlans in the traditional sense (unlug the cable/disconnet WIFI), the network card on your device would automatically release the IP address and get a new one when you "plug it back" to the other vlan. I can only guess that you are not doing this (or the digital equivelent of this assuming it is a vNIC) – Mucker Aug 28 '23 at 10:17
  • That's literally what I am doing though...to switch the VLAN I have to physically put the ethernet cable into another outlet. – paddex Aug 28 '23 at 19:21

0 Answers0