bind plugin: lots of 'dispatch error ... host unreachable'

[dinguz]

Upon install of the bind plugin, I'm lots of these errors:

16-Dec-2019 09:30:06.353 dispatch: error: dispatch 0x42f7da3c400: shutting down due to TCP receive error: 199.254.50.1#53: host unreachable
16-Dec-2019 09:30:06.611 dispatch: error: dispatch 0x42f7da3c400: shutting down due to TCP receive error: 199.254.48.1#53: host unreachable
16-Dec-2019 09:30:06.645 dispatch: error: dispatch 0x42f7da3c400: shutting down due to TCP receive error: 199.249.121.1#53: host unreachable

For anyone also seeing this, they can be resolved by setting the following tunable:

net.inet.tcp.soreceive_stream: 0

The default is 1. Perhaps this should be in the documentation somewhere.