ZyXEL Communications USG 2000 User Manual

Page of 1081
 Chapter 13 Interfaces
ZyWALL USG 2000 User’s Guide
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If computer B responds to computer A, bridge X records the source address 
0B:0B:0B:0B:0B:0B and port 4 in the table. It also looks up 0A:0A:0A:0A:0A:0A 
in the table and sends the packet to port 2 accordingly.
Bridge Interface Overview
A bridge interface creates a software bridge between the members of the bridge 
interface. It also becomes the ZyWALL’s interface for the resulting network.
Unlike the device-wide bridge mode in ZyNOS-based ZyWALLs, this ZyWALL can 
bridge traffic between some interfaces while it routes traffic for other interfaces. 
The bridge interfaces also support more functions, like interface bandwidth 
parameters, DHCP settings, and connectivity check. To use the whole ZyWALL as a 
transparent bridge, add all of the ZyWALL’s interfaces to a bridge interface. 
A bridge interface may consist of the following members:
• Zero or one VLAN interfaces (and any associated virtual VLAN interfaces)
• Any number of Ethernet interfaces (and any associated virtual Ethernet 
interfaces)
When you create a bridge interface, the ZyWALL removes the members’ entries 
from the routing table and adds the bridge interface’s entries to the routing table. 
For example, this table shows the routing table before and after you create bridge 
interface br0 (250.250.250.0/23) between ge1 and vlan1. 
In this example, virtual Ethernet interface ge1:1 is also removed from the routing 
table when ge1 is added to br0. Virtual interfaces are automatically added to or 
remove from a bridge interface when the underlying interface is added or 
removed.
Table 69   Example: Bridge Table After Computer B Responds to Computer A
MAC ADDRESS
PORT
0A:0A:0A:0A:0A:0A
2
0B:0B:0B:0B:0B:0B
4
Table 70   Example: Routing Table Before and After Bridge Interface br0 Is Created
IP ADDRESS(ES)
DESTINATION
IP ADDRESS(ES)
DESTINATION
210.210.210.0/24
ge1
221.221.221.0/24
vlan0
210.211.1.0/24
ge1:1
230.230.230.192/26
ge3
221.221.221.0/24
vlan0
241.241.241.241/32
ge4
222.222.222.0/24
vlan1
242.242.242.242/32
ge5
230.230.230.192/26
ge3
250.250.250.0/23
br0
241.241.241.241/32
ge4
242.242.242.242/32
ge5