33

Device HA

Use device HA and Virtual Router Redundancy Protocol (VRRP) to increase network reliability. See Section 5.4.8 on page 117 for related information on these screens.

33.1 Virtual Router Redundancy Protocol (VRRP) Overview

Every computer on a network may send packets to a default gateway, which can become a single point of failure. Virtual Router Redundancy Protocol (VRRP) allows you to create redundant backup gateways to ensure that the default gateway is always available.

"The ZyWALL runs VRRP v2. You can only set up device HA with other ZyWALLs of the same model running the same firmware version.

In VRRP, a virtual router represents a number of routers associated with one IP address, the IP address of the default gateway. Each virtual router is identified by a unique 8-bit identification number called a Virtual Router ID (VR ID). In the example below, Router A and Router B are part of virtual router 10 with IP address 192.168.10.254.

Figure 363 Example: VRRP, Normal Operation

The VR ID is not shown. In normal operation, Router A is the master router. It has the same IP address as the default gateway and forwards traffic for the network. Router B is a backup router. It is using its management IP address 192.168.10.112. Router A sends regular messages to Router B to let Router B know that Router A is available. The time interval between these messages is called the advertisement interval.

 

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ZyWALL USG 300 User’s Guide