? "dhcp.c:4131: Failed to send 306 byte long packet over fallback interface." ?

[mscd]

Hello,

we are using OPNsense OPNsense 22.1.8-amd64 installed on two (former) Sophos SG-310 boxes in a PFSYNC-cluster setup up. At the moment we repeatedly (every minute) observe the following errors in the DHCPv4 log files:

Code Select Expand


2022-05-26T09:05:14 Error dhcpd dhcp.c:4131: Failed to send 306 byte long packet over fallback interface.
2022-05-26T09:05:14 Error dhcpd send_packet: Host is down
2022-05-26T09:05:02 Error dhcpd dhcp.c:4131: Failed to send 306 byte long packet over fallback interface.
2022-05-26T09:05:02 Error dhcpd send_packet: Host is down
...

I have already done some research at google, but at the moment I can't figure out exactly the meaning/source of these error messages. What is the meaning of "fallback interface" in conjunction to the DHCPv4 service?

Can we ignore these messages?

Best regards,
mscd

[_Alchemist_]

Have you set anything up in "Services --> DHCPv4 --> [Interface Name] --> Failover peer IP" ?
If so, are the IP addresses correct?

[mscd]

I am using the option "failover-ip" ... always (correctly) configured to the IP address of the backup OPNsense machine. On the backup machine the logs show:

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2022-05-26T10:48:21 Error dhcpd bind update on 10.130.3.90 from dhcp_opt12 rejected: incoming update is less critical than outgoing update
2022-05-26T10:43:22 Error dhcpd bind update on 10.130.2.29 from dhcp_opt12 rejected: incoming update is less critical than outgoing update
2022-05-26T10:31:50 Error dhcpd bind update on 10.129.1.199 from dhcp_opt11 rejected: incoming update is less critical than outgoing update
2022-05-26T10:19:56 Error dhcpd dhcp.c:4131: Failed to send 300 byte long packet over fallback interface.
2022-05-26T10:19:56 Error dhcpd send_packet: Host is down
2022-05-26T10:19:43 Error dhcpd dhcp.c:4131: Failed to send 300 byte long packet over fallback interface.
2022-05-26T10:19:43 Error dhcpd send_packet: Host is down
2022-05-26T10:19:36 Error dhcpd dhcp.c:4131: Failed to send 300 byte long packet over fallback interface.
2022-05-26T10:19:36 Error dhcpd send_packet: Host is down
2022-05-26T10:19:19 Error dhcpd dhcp.c:4131: Failed to send 300 byte long packet over fallback interface.
2022-05-26T10:19:19 Error dhcpd send_packet: Host is down
2022-05-26T10:19:03 Error dhcpd dhcp.c:4131: Failed to send 300 byte long packet over fallback interface.
2022-05-26T10:19:03 Error dhcpd send_packet: Host is down
2022-05-26T10:18:54 Error dhcpd dhcp.c:4131: Failed to send 300 byte long packet over fallback interface.
2022-05-26T10:18:54 Error dhcpd send_packet: Host is down