Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) - Manual (Page 803)

Multi-Service IronWare Routing Configuration Guide 775
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Overview of VRRP
FIGURE 39 Router1 is Host1’s default gateway but is a single point of failure
As shown in this example, Host1 uses 192.53.5.1 on Router1 as the host’s default gateway out of
the subnet. If this interface goes down, Host1 is cut off from the rest of the network. Router1 is
thus a single point of failure for Host1’s access to other networks.
If Router1 fails, you could configure Host1 to use Router2. Configuring one host with a different
default gateway might not require too much extra administration. However, consider a more
realistic network with dozens or even hundreds of hosts per subnet; reconfiguring the default
gateways for all the hosts is impractical. It is much simpler to configure a VRRP virtual router on
Router1 and Router2 to provide a redundant path for the hosts. If VRRP is enabled as in
Figure 40 ,
Router2 provides the default gateway out of the subnet if Router1 fails.