Interface grouping is available on FreeBSD and OpenBSD. This will allow
you to enumerate only SoftEther virtual interfaces or exclude SoftEther
virtual interfaces, and be helpful when making custom scripts to start
DHCP client when virtual interface become up (=VPN connection
established) for example.
Usage examples as follows.
List all interfaces' names available on the system:
```
$ ifconfig -l
vtnet0 lo0 vpn_client0 vpn_client1 vpn_client2
```
Display a list of SoftEther virtual interfaces:
```
$ ifconfig -g softether
vpn_client0
vpn_client1
vpn_client2
```
Display details about SoftEther virtual interfaces that are up:
```
$ ifconfig -a -u -g softether
vpn_client0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: SoftEther Virtual Network Adapter
options=80000<LINKSTATE>
ether 5e:71:fa:f8:91:4a
hwaddr 58:9c:fc:10:34:2a
groups: tap softether
media: Ethernet autoselect
status: active
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
Opened by PID 1445
```
Display details about interfaces except for SoftEther virtual interfaces:
```
$ ifconfig -a -G softether
vtnet0: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=80028<VLAN_MTU,JUMBO_MTU,LINKSTATE>
ether 58:9c:fc:00:f0:23
inet6 fe80::5a9c:fcff:fe00:f023%vtnet0 prefixlen 64 scopeid 0x1
inet 192.168.96.7 netmask 0xffffff00 broadcast 192.168.96.255
media: Ethernet autoselect (10Gbase-T <full-duplex>)
status: active
nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2
inet 127.0.0.1 netmask 0xff000000
groups: lo
nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
```
In contrast to Linux, FreeBSD's tap devices are still plumbed after fd
closed. The tap device must be destroyed in addition to closing fd
to delete virtual network interfaces used for VPN connection.
NicDelete command now works properly and virtual network interfaces used
by vpnclient are cleaned up when shutting down vpnclient.
On startup client creates TUN interface in UP state and kept it UP even
if connection to the server was lost. Creating interface in DOWN state,
turning it UP on successful (re-)connection to server and DOWN on either
disconnect or connection loss would enable DHCP client (say dhclient5)
to detect necessity for lease renewal.
Added a client configuration parameter to create TUN interface in DOWN
state and commands to enable, disable, and query the configuration
parameter.
Enabling the parameter causes client to put all unused TUN interfaces
DOWN, create new TUN interfaces in DOWN state, and turn TUN interfaces
corresponding to active sessions DOWN on connection loss or
disconnecting from server.
Disabling the parameter forces client to turn all TUN interfaces UP and
create new TUN interfaces in UP state.
Default value is 'Disable'.
