Brocade Communications Systems ICX 7250 series, Configuration Manual

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FIGURE 32 Single point of failure with Device 1 being the Host1 default gateway
To connect to the Internet or an internal intranet Host 1, in the figure, uses the IP address of 10.53.5.1 on Router 1 as its default
gateway. If this interface goes down, Host1 is cut off from the rest of the network. Router 1 is a single point of failure for Host 1 to access
other networks. In small networks, the administrative burden of configuring Router 2 as the new default gateway is not an issue, but in
larger networks reconfiguring default gateways is impractical. Configuring a VRRP virtual router on Router 1 and Router 2 provides a
redundant path for the hosts. VRRP allows you to provide alternate router paths for a host without changing the IP address or MAC
address by which the host knows its gateway.
To illustrate how VRRP works, the following figure shows the same network, but a VRRP virtual router is configured on the two physical
routers, Router 1 and Router 2. This virtual router provides redundant network access for Host 1. If Router 1 were to fail, Router 2 would
provide the default gateway out of the subnet.
VRRPv2 overview
Brocade FastIron Layer 3 Routing Configuration Guide
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