[tor-relays] unbound: error: recvfrom 123 failed: Host is down

[Winter Paulson]

Hello,

I'm running an exit relay > 200 Mbit/s with local unbound on openbsd. I
receive a lot of the following syslog messages from unbound:

unbound: [15040:1] error: recvfrom 226 failed: Host is down


I already increased the UDP buffer sizes:

net.inet.udp.sendspace: 262144
net.inet.udp.recvspace: 262144


(hopefully) relevant part from unbound.conf is:

num-threads: 2
msg-cache-slabs: 4
rrset-cache-slabs: 4
infra-cache-slabs: 4
key-cache-slabs: 4
rrset-cache-size: 100m
msg-cache-size: 50m
outgoing-range: 450
outgoing-port-avoid:
"22,25,26,37,54,55,67,68,69,80,110,123,135,137,138,139,143,443,445,465,500,587,843,990,912,993,995,1025,1863,1935,2400,4242,4400,4421,4444,4445,4480,4500,4569,5038,5050,5060,5061,5062,5063,5064,5065,5198,5199,5200,5222,5555,5800,5801,5900,5901,6666,6667,6668,6669,7000,7001,7002,7003,7004,7005,7006,7658,7659,7660,7777,8050,8052,8054,8056,8058,8060,8080,8110,8118,8120,8123,8125,8143,8998,9001,9022,9030,9050,9051,9052,9053,9054,9055,9056,9057,9058,9059,9060,9080,10000,15000,15001,15002,15003,15004,16001,16999,20000,20001,25000,26999,29998,30600,31000,32000,36999,50300"
outgoing-num-tcp: 25
incoming-num-tcp: 25
msg-buffer-size: 65552


I couldn't find any hints on the internet apart from increasing UDP
buffers, any ideas what else to look for?

Thank you!

w.