DHCP HA communication fails after upgrading the device from 1.4.4 version to the Stream release 2026.02. In 1.4 ISC DHCP, the high-availability option name accepts a descriptive name and expects the same value to be defined on both primary and secondary DHCP servers.
Whereas in 1.5, the KEA DHCP server expects the peer’s hostname to be defined in the option "name" for successful high-availability communication, which is picked from the section define in /run/kea/kea-dhcp4.conf file
:"parameters": {
"high-availability": [{"this-server-name": "dhcp-server01", "mode": "hot-standby", "heartbeat-delay": 10000, "max-response-delay": 10000, "max-ack-delay": 5000, "max-unacked-clients": 0, "peers": [{"name": "dhcp-server01", "url": "http://192.168.12.2:647/", "role": "primary", "auto-failover": true}, {"name": "dhcp-server02", "url": "http://192.168.12.3:647/", "role": "standby", "auto-failover": true}]}]Primary dhcp server:
set service dhcp-server high-availability name 'dhcp-server02'
https://docs.vyos.io/en/latest/configuration/service/dhcp-server.html#example
Error after upgrading from 1.4 to 1.5 version:
Mar 17 11:44:31 kea-dhcp4[2200]: 2026-03-17 11:44:31.097 INFO [kea-dhcp4.commands/2200.139911089342144] COMMAND_RECEIVED Received command 'ha-heartbeat' Mar 17 11:44:37 kea-dhcp4[2200]: 2026-03-17 11:44:37.856 WARN [kea-dhcp4.ha-hooks/2200.139911097734848] HA_HEARTBEAT_FAILED dhcp-server01: heartbeat to dhcp-server02 (http://192.168.12.3:647/) failed: dhcp-server01 matches no configured 'server-name' (error code 1) Mar 17 11:44:37 kea-dhcp4[2200]: 2026-03-17 11:44:37.857 WARN [kea-dhcp4.ha-hooks/2200.139911097734848] HA_COMMUNICATION_INTERRUPTED dhcp-server01: communication with dhcp-server02 is interrupted Mar 17 11:44:41 kea-dhcp4[2200]: 2026-03-17 11:44:41.108 INFO [kea-dhcp4.commands/2200.139911089342144] COMMAND_RECEIVED Received command 'ha-heartbeat' Mar 17 11:44:47 kea-dhcp4[2200]: 2026-03-17 11:44:47.869 WARN [kea-dhcp4.ha-hooks/2200.139911097734848] HA_HEARTBEAT_FAILED dhcp-server01: heartbeat to dhcp-server02 (http://192.168.12.3:647/) failed: dhcp-server01 matches no configured 'server-name' (error code 1)
Error observed in 1.4 when different names are configured:
Mar 17 11:24:36 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:36 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:38 dhcpd[3231]: DHCPREQUEST for 192.168.12.142 from 0c:af:0d:eb:00:00 (vyos) via eth1: not responding (recovering) Mar 17 11:24:41 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:41 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:46 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:46 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:48 dhcpd[3231]: DHCPREQUEST for 192.168.12.142 from 0c:af:0d:eb:00:00 (vyos) via eth1: not responding (recovering) Mar 17 11:24:51 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:51 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:56 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner. Mar 17 11:24:56 dhcpd[3231]: Failover CONNECT to dhcp-server02 rejected: Connection rejected, invalid failover partner.
Configuration attached.