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Date: Wed, 01 Apr 2015 12:13:41 +0200
From: Miroslav Lachman <000.fbsd@quip.cz>
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To: Yuri <yuri@rawbw.com>, net@freebsd.org
Subject: Re: tap(4): will it be more reasonable if it preserved
 UP/DOWN state, when closed?
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Yuri wrote on 04/01/2015 01:39:
> Currently tap(4) device gets to 'down' state when the last process
> closes it, regardless of the original 'up/down' state.
> Will it be reasonable to modify this behavior and keep this bit
> 'was_up_before_open', and leave it 'up' if it was 'up' when it was first
> opened?
>
> Practically speaking, I set it up in rc.conf to be 'up' with the
> particular IP, but it goes to 'down' state  when VirtualBox closes it.
>
> If tap(4) can be 'up' without users, there shouldn't be any problem in
> leaving it 'up' after use as well?

Doesn't sysctl net.link.tap.up_on_open=1 fix your problem?

Miroslav Lachman