Re: Server Unreachable - Network Interface Errors Observed in Logs

On 24.3.2026 08:00, Mark wrote:
> Hello,
>
> I am operating a dedicated server configured as both a web and mail
> server. Earlier today, the system became completely unresponsive,
> including failure to respond to ICMP (ping) requests.
>
> I contacted the hosting provider and requested a reboot. Following the
> reboot, the server returned to normal operation.
>
> Upon reviewing the system logs, I identified the following entries
> from the previous night:
>
>
> Mar 24 03:17:18 mail /bsd: re0: watchdog timeout
> Mar 24 03:17:22 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:17:23 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:17:26 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:17:27 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:17:29 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:17:33 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:17:41 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:17:58 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:18:30 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:19:34 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:20:38 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:21:42 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:22:47 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:23:51 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:24:55 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
> Mar 24 03:25:59 mail dhcpleased[99738]: bpf_send_packet: writev: No
> buffer space available
>
> These messages appear to indicate a network interface issue (re0
> watchdog timeout) followed by failures in packet transmission due to
> insufficient buffer space.
>
> Could you please provide insight into the possible root cause of this
> behavior, and whether it is likely related to a driver, hardware, or
> network stack issue?
>
> Any guidance would be greatly appreciated.

https://www.openbsd.org/mail.html

especially Netiquette part and how to include important information

Besides that it may be nice to see eg. output of 'netstat -m'

>
> Server: amd64 - OpenBSD 7.8 (GENERIC.MP) #6:
>
> Thank you,
> Mark