FreeBSD 8 as VirtualBox guest: `ngctl list` shows nothing

[Anh Ky Huynh]

Hi all,

I have a VirtualBox guest which is running FreeBSD-8.0. I compiled the kernel for this guest with the options NETGRAPH in /usr/src/sys/i386/conf/GENERIC. I did that because I expected I would see each Ethernet interface as a netgraph node. But ngctl showed nothing

$ ngctl
There are 3 total nodes:
  Name: <unnamed>       Type: ksocket         ID: 00000008   Num hooks: 1
  Name: ng0             Type: iface           ID: 00000006   Num hooks: 1
  Name: ngctl1633       Type: socket          ID: 00000013   Num
  hooks: 0

(doesnot contain em0, em1,..)

This is different from the output for my real FreeBSD host

$ ngctl list
There are 5 total nodes:
  Name: re0             Type: ether           ID: 00000001   Num hooks: 2
  Name: ngctl15142      Type: socket          ID: 00000006   Num hooks: 0
  Name: vboxnetflt_re0  Type: vboxnetflt      ID: 00000004   Num hooks: 2
  Name: vboxnet0        Type: ether           ID: 00000003   Num hooks: 0
  Name: wlan0           Type: ether           ID: 00000002   Num
  hooks: 0

(contains re0, wlan0)

Why are they different?

Thank you for replies,

Regards,

-- 
Anh Ky Huynh

PS: Below the output of $ifconfig in the VirtualBox guest

$ ifconfig
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 08:00:27:d0:6e:ab
        inet 192.168.1.17 netmask 0xffffff00 broadcast 192.168.1.255
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
em1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
        ether 08:00:27:bf:a8:d1
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=3<RXCSUM,TXCSUM>
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x5 
        inet6 ::1 prefixlen 128 
        inet 127.0.0.1 netmask 0xff000000 
epair0b: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        ether 02:c0:84:00:07:0b
        inet 10.0.3.1 netmask 0xffffff00 broadcast 10.0.3.255
        inet 10.0.3.3 netmask 0xffffff00 broadcast 10.0.3.255
ng0: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> metric 0 mtu 1500