Unclear messages in log

Hi All,

my unbound v1.6.0-3+deb9u2 servers were hit for short periods of time by traffic that generated a lot of log messages that look like

unbound: [879:2] notice: sendmsg failed: Invalid argument

unbound: [879:2] notice: remote address is port 22653

I can not find any clear documentation on this messages. In fact, the whole mailing list archive only has three emails mentioning this message.

Can someone enlighten me on their meaning and shed some light on a possible cause?

Thanks in advance.

Sincerely,

Jan.

May be, upgrade Unbound first? Current version is 1.10.1.

my unbound v1.6.0-3+deb9u2 servers

looks like your using Debian Stretch. This packages was build Feb 2017
https://sources.debian.org/src/unbound/1.6.0-3+deb9u2/debian/changelog/

unbound: \[879:2\] notice: sendmsg failed: Invalid argument

some functional and bugfix updates are releases till now, the current unbound version 1.10.1

An upgrade to Debian buster allows you to use a newer version up to the latest avialable via buster backports.
https://packages.debian.org/search?keywords=unbound&searchon=names&suite=all&section=all

Andreas