Redundancy; Vrrp Con Guration - NetModule NB2800 User Manual

5.7.13. Redundancy

This page can be used to set up a redundant pair of NetModule routers (or other systems)
by running the Virtual Router Redundancy Protocol (VRRP) between them. A typical VRRP
scenario de nes a rst host playing the master and another the backup device, they both
de ne a virtual gateway IP address which will be distributed by gratuitous ARP messages for
updating the ARP cache of all LAN hosts and thus redirecting the packets accordingly.
A takeover will happen within approximately 3 seconds as soon as the partner is not reach-
able anymore (checked via multicast packets). This may happen when one device is reboot-
ing or the Ethernet link went down. Same applies when the WAN link goes down.
In case DHCP has been activated, please keep in mind that you will need to recon gure the
DHCP gateway address offered by the server and let them point to the virtual gateway ad-
dress. In order to avoid con icts you may turn off DHCP on the backup device or even better,
split the DHCP lease range across both routers in order to prevent any lease duplication.
Parameter
Administrative status
Role
VID
NB2800 User Manual 4.2
Figure 5.47.: VRRP Con guration
Redundancy Con guration
Administrative status
The role of this system (either master or backup)
The Virtual Router ID (you can theoretically run multiple in-
stances)
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