From owner-freebsd-net@freebsd.org  Thu Apr 19 07:03:46 2018
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Subject: Re: max devices in tun
To: Akilan Elango <akilan1997@gmail.com>, freebsd-net@freebsd.org
References: <CABTkBy_7QpX8F+5bai-BXtLbZGEXcgfh69-8Ni+k_apBq4t-SQ@mail.gmail.com>
From: Eugene Grosbein <eugen@grosbein.net>
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Date: Thu, 19 Apr 2018 14:03:17 +0700
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19.04.2018 7:29, Akilan Elango wrote:

> Hey guys,
>     I was fiddling around with the /dev/tun to write a TUN interface
> for my app. I wanted to check what is the max amount of interfaces
> that can be made. Turned out it was 32768 [0 - 32768). But when I
> created (ifconfig tun32768 create), a weird device appeared as shown
> in this figure : https://imgur.com/a/0ypbwgg.
> 
> Is this expected? and I'm unable to delete the device too from ifconfig.

You should tell what FreeBSD version do you use.
It does not do so for my 11.1/i386:

# ifconfig tun32768 create
ifconfig: SIOCIFCREATE2: No space left on device