RuggedCom RuggedRouter RX1100 - Manual (Page 191)

19. Configuring VRRP
Revision 1.14.3 191 RX1000/RX1100™
In the following network, both host 1 and host 2 use a gateway of 192.168.3.10. The external side can
access the internal side by gateway 192.168.2.10. The VRID_20 and VRID_21 are grouped together.
Normally the Router 1 will provide both internal and external access gateway as its priority is higher
than those on Router 2. When either internal or external side of Router 1 becomes inoperative, it will
remove the control of both VRIP 192.168.2.10 and 192.168.3.10 and gives the control to Router 2.
Figure 19.2. VRRP Group Example
Other VRRP parameters are the Advertisement Interval and Gratuitous ARP Delay.
The advertisement interval is the time between which advertisements are sent. A backup router will
assume mastership four advertisement intervals after the master fails, so the minimum fail-over
time is four seconds. If a monitored interface goes down, a master router will immediately signal an
election and allow a backup router to assume mastership.
The router issues a set of gratuitous ARPs when moving between master and backup state. These
unsolicited ARPs teach the hosts and switches in the network of the current MAC address and port
associated with the VRIP. The router will issue a second set of ARPs after the time specified by the
Gratuitous ARP delay.