bhyve on reboot loses tap(4) configuration

Bjoern A. Zeeb bzeeb-lists at
Mon Oct 15 16:14:09 UTC 2018

On 15 Oct 2018, at 16:10, Marcelo Araujo wrote:

> Em ter, 16 de out de 2018 às 00:06, Bjoern A. Zeeb <
> bzeeb-lists at> escreveu:
>> Hi,
>> I tried to use bhyve with the tap(4)/vtnet(4) solution as documented 
>> in
>> the handbook (tap needs autoopen).
>> However, I am using no bridge(4) interface but a “point-to-point”
>> configuration.
>> Example:
>> guest configures vtnet0 to
>> host configures tap0 to
>> When rebooting the guest inside the bhyve, it seems bhyve loses the
>> outside tap0 configuration.  I assume that is because the tap0 
>> interface
>> is closed and re-opened on the “warm restart”.
>> Apart from using devd and possibly tracking tap interfaces to come up
>> and track things there, is there are better solution for not having 
>> to
>> reconfigure the host interface on every guest reboot?
> Not sure if I understood well your case, but have you tried to set 
> this
> sysctl:

That only ensures that effectively “an ifconfig tap<n> up” gets 

The problem, as I assume is, if you close /dev/tap and re-open /dev/tap 
it seems the configuration (interface addresses) seem to be cleaned up 
on “close”.


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