ZyXEL Communications 200 Series User Manual

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Chapter 10 Interface
ZyWALL USG 100/200 Series User’s Guide
200
10.1.2  What You Need to Know About Interfaces
Interface Characteristics
Interfaces generally have the following characteristics (although not all characteristics apply 
to each type of interface).
• An interface is a logical entity through which (layer-3) packets pass.
• An interface is bound to a physical port or another interface.
• Many interfaces can share the same physical port.
• An interface belongs to at most one zone.
• Many interfaces can belong to the same zone.
• Layer-3 virtualization (IP alias, for example) is a kind of interface.
Types of Interfaces
You can create several types of interfaces in the ZyWALL.
• Setting interfaces to the same port role forms a port group. This creates a hardware 
connection between the physical ports at the layer-2 (data link, MAC address) level. 
• Ethernet interfaces are the foundation for defining other interfaces and network policies. 
RIP and OSPF are also configured in these interfaces.
• PPP interfaces support Point-to-Point Protocols (PPPoE or PPTP). ISP account settings 
are included.
• Cellular interfaces are for 3G WAN connections via a connected 3G device.
• WLAN interfaces are for wireless LAN (IEEE 802.11b/g) connections via an installed 
wireless LAN card.
• VLAN interfaces receive and send tagged frames. The ZyWALL automatically adds or 
removes the tags as needed. Each VLAN can only be associated with one Ethernet 
interface.
• Bridge interfaces create a software connection between Ethernet or VLAN interfaces at 
the layer-2 (data link, MAC address) level. Unlike port groups, bridge interfaces can take 
advantage of some security features in the ZyWALL. You can also assign an IP address 
and subnet mask to the bridge.
• Virtual interfaces provide additional routing information in the ZyWALL. There are 
three types: virtual Ethernet interfacesvirtual VLAN interfaces, and virtual bridge 
interfaces
.
• The auxiliary interface, along with an external modem, provides an interface the 
ZyWALL can use to dial out. This interface can be used as a backup WAN interface, for 
example. The auxiliary interface controls the AUX port.
• Trunks manage load balancing between interfaces.