ZyXEL Communications ZyWALL 300 User Manual

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Chapter 33 Device HA
ZyWALL USG 300 User’s Guide
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33.2.1  Link Monitoring and Service Control
With link monitoring enabled, a backup ZyWALL that takes over for an unavailable master 
ZyWALL takes over all of the master ZyWALL’s static IP addresses. This way the backup 
ZyWALL takes over all of the master ZyWALL’s functions. However, this also means you 
can no longer access the original master ZyWALL through one of its static IP addresses 
(because the backup ZyWALL now uses this address). Do one of the following to still be able 
to access the original master ZyWALL (assuming it is still functioning).
• Use a DHCP client interface. The DHCP server assigns the backup ZyWALL an IP 
address that is different from the IP address assigned to the master ZyWALL. So you can 
still access the original master ZyWALL through its DHCP assigned IP address. You will 
need some way to know the dynamic IP address assigned to the master ZyWALL’s 
interface. One way is to set the master ZyWALL to use DDNS. Or, if you have access to 
the DHCP server, you can check it to see what IP address it assigned to the master 
ZyWALL. 
• Use a static IP address on one of the master ZyWALL’s interfaces without adding that 
interface to any VRRP group. Also leave the corresponding port on the backup ZyWALL 
unconnected. This way the original master ZyWALL still uses the static IP address after 
the backup ZyWALL takes over for it.
• Connect an external serial modem to the AUX port and configure dial-in management.
33.3  Device HA Screens
The VRRP Group summary screen provides information about which interfaces are in virtual 
routers and the role and status of each interface in the virtual router.
The VRRP Group Add/Edit screen allows you to add VRRP groups to the ZyWALL or to 
edit the configuration of an existing VRRP group. You have to go to the VRRP Group 
summary screen first to access this screen.
You can use the Synchronize screen to make sure all ZyWALLs in the VRRP group have the 
same updated certificates, AV signatures, IDP and application patrol signatures, system 
protect signatures, and configuration information, regardless of whether each router is the 
master router or a backup router.
33.4  VRRP Group Summary
The VRRP Group summary screen provides information about which interfaces are in virtual 
routers and the role and status of each interface in the virtual router. To access this screen, 
click Device HA.