"dhclient: send_packet: No buffer space available"

[Yoshihiro Ota]

Hi,

I recently switched internet service provider and got much faster connection.
However, I started seeing some unstable connections between the WiFi router and FreeBSD.
I was on FreeBSD 12.0-RELEASE and switched to 12.1-RELEASE.
Both versions have same symptoms.

I get "dhclient: send_packet: No buffer space available" to console and then I frequently lose connection after seeing it.
After taking the wlan down and re-connect it with wpa_supplicant, I usually get a connection back.

On the side note, I also see these outputs to console and syslog:
ath0: bb hang detected (0x4), resetting
ath0: ath_legacy_rx_tasklet: sc_inreset_cnt > 0; skipping

Does anyone have any advice how to fix/work-around or where to start looking: ath driver, dhclinet, kernel, wlan, and/or wpa_supplicant?

Thanks,
Hiro