ZyXEL Communications 1000 사용자 설명서

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Chapter 13 Interfaces
ZyWALL USG 1000 User’s Guide
332
For example, if the ZyWALL gets a packet with a destination address of 
100.100.25.25, it routes the packet to interface ge1. If the ZyWALL gets a packet 
with a destination address of 200.200.200.200, it routes the packet to interface 
ge2.
In most interfaces, you can enter the IP address and subnet mask manually. In 
PPPoE/PPTP interfaces, however, the subnet mask is always 255.255.255.255 
because it is a point-to-point interface. For these interfaces, you can only enter 
the IP address.
In many interfaces, you can also let the IP address and subnet mask be assigned 
by an external DHCP server on the network. In this case, the interface is a DHCP 
client. Virtual interfaces, however, cannot be DHCP clients. You have to assign the 
IP address and subnet mask manually.
In general, the IP address and subnet mask of each interface should not overlap, 
though it is possible for this to happen with DHCP clients.
In the example above, if the ZyWALL gets a packet with a destination address of 
5.5.5.5, it might not find any entries in the routing table. In this case, the packet 
is dropped. However, if there is a default router to which the ZyWALL should send 
this packet, you can specify it as a gateway in one of the interfaces. For example, 
if there is a default router at 200.200.200.100, you can create a gateway at 
200.200.200.100 on ge2. In this case, the ZyWALL creates the following entry in 
the routing table.
The gateway is an optional setting for each interface. If there is more than one 
gateway, the ZyWALL uses the gateway with the lowest metric, or cost. If two or 
more gateways have the same metric, the ZyWALL uses the one that was set up 
first (the first entry in the routing table). In PPPoE/PPTP interfaces, the other 
computer is the gateway for the interface by default. In this case, you should 
specify the metric.
If the interface gets its IP address and subnet mask from a DHCP server, the DHCP 
server also specifies the gateway, if any.
Interface Parameters 
The ZyWALL restricts the amount of traffic into and out of the ZyWALL through 
each interface.
Table 76   Example: Routing Table Entry for a Gateway
IP ADDRESS(ES)
DESTINATION
0.0.0.0/0
200.200.200.10
0