FYI: I avoided this problem entirely by configuring a stable 'client-id' in NetworkManager on the laptops in question. They now get the same address (via host reservation) regardless of the connection method, and only a single reservation is required in Kea for each one.
On Sat, Jan 29, 2022 at 9:46 AM Kevin P. Fleming <[email protected]> wrote: > > Hello there! I've just deployed Kea 2.0.1 (using the ISC packages) on > a pair of machines in my network to provide HA DHCP4/DHCP6 services > (replacing the ISC DHCPd-based service in my layer 3 switches, which > don't provide sufficient functionality for my needs). > > I've got the daemons running and HA mode working; most DHCP4 > functionality is working fine. > > However, one feature of Kea DHCP that I'd like to use is 'multiple > reservations for the same IP address', which was enabled when the > 'ip-reservations-unique' configuration option was added. In my case I > have laptops with both WiFi and Ethernet connections, with different > MAC addresses, but I want them to have the same IP addresses > regardless of the connection mode. They will never be connected via > both interfaces at once, in fact the laptop BIOSes have been > configured to 'rfkill' the WiFi interfaces when the Ethernet > interfaces are connected. > > I've posted a copy of my configuration here: https://km6g.us/kea-dhcp4.conf > > If you take a look at subnet4 id '88', you'll see two reservations for > 'balrog22' with the same IP address but different MAC addresses. While > the DHCP4 server accepts this configuration, when the laptop attempts > to obtain an address the server logs a message complaining about the > duplication: > > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: WARN > ALLOC_ENGINE_V4_DISCOVER_ADDRESS_CONFLICT [hwtype=1 > a8:64:f1:30:88:0b], cid=[01:a8:64:f1:30:88:0b], tid=0xcf6b412e: > conflicting reservation for address 192.168.88.192 with existing lease > Address: 192.168.88.192 > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: Valid life: 86400 > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: Cltt: 1643462468 > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: Hardware addr: 90:2e:16:d6:a4:1e > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: Client id: (none) > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: Subnet ID: 88 > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: State: default > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: INFO DHCP4_LEASE_ADVERT > [hwtype=1 a8:64:f1:30:88:0b], cid=[01:a8:64:f1:30:88:0b], > tid=0xcf6b412e: lease 192.168.88.128 will be advertised > Jan 29 09:39:10 edge21-b kea-dhcp4[725279]: INFO DHCP4_LEASE_ALLOC > [hwtype=1 a8:64:f1:30:88:0b], cid=[01:a8:64:f1:30:88:0b], > tid=0xcf6b412e: lease 192.168.88.128 has been allocated for 86400 > seconds > > Have I overlooked something in the configuration, or am I trying to > use this feature in a way that it is not expected to operate? -- 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 [email protected] https://lists.isc.org/mailman/listinfo/kea-users
