30.11. VLANs

VLANs are a way of virtually dividing up a network into many different subnetworks. Each will have its own broadcast domain and be isolated from the rest of the VLANs.

在 FreeBSD 上,要使用 VLANs 必須有網路卡驅動程式的支援,要查看那些驅動程式支援 vlan,請參考 vlan(4) 操作手冊。

When configuring a VLAN, a couple pieces of information must be known. First, which network interface? Second, what is the VLAN tag?

To configure VLANs at run time, with a NIC of em0 and a VLAN tag of 5. The command would look like this:

# ifconfig em0.5 create vlan 5 vlandev em0 inet 192.168.20.20/24

注意:

See how the interface name includes the NIC driver name and the VLAN tag, separated by a period? This is a best practice to make maintaining the VLAN configuration easy when many VLANs are present on a machine.

To configure VLANs at boot time, /etc/rc.conf must be updated. To duplicate the configuration above, the following will need to be added:

vlans_em0="5"
ifconfig_em0_5="inet 192.168.20.20/24"

Additional VLANs may be added, by simply adding the tag to the vlans_em0 field and adding an additional line configuring the network on that VLAN tag's interface.

本文及其他文件,可由此下載: ftp://ftp.FreeBSD.org/pub/FreeBSD/doc/

若有 FreeBSD 方面疑問,請先閱讀 FreeBSD 相關文件,如不能解決的話,再洽詢 <questions@FreeBSD.org>。

關於本文件的問題,請洽詢 <doc@FreeBSD.org>。