tun interfaces should not be hidden from Interfaces>assign
tunX interfaces are hidden from assignment and should not be. they're useful in a number of circumstances when manually hacking in services that use them, like Cisco VPN client.
current work around to remove tun from line 713 (RELENG_2_0) in util.inc.
Updated by Ermal Luçi about 12 years ago
Probably just rename the interface as we do for openvpn.
Otherwise some consequenceis might arise.
Most all of the utility allow running a script or giving the name of a static interface to accomplish this. Since tun/tap are used from a lot of applications that will have the same requirment and give problems.