Redundancy 3 - M2M IDG701AM-0T001 User Manual

M2M Cellular Gateway
5.7 Redundancy
In engineering, redundancy is the duplication of critical components or functions of a system with
the intention of increasing reliability of the system, usually in the form of a backup or fail‐safe. In an IP
networking, the access gateway is the critical part of the networking system. Redundant gateway plays
the backup one of the master gateway and it will take over the data transmitting job once it finds the
master gateway failed.
AMIT security gateway can serve as the redundant gateway of core router in the enterprise by
using the Virtual Router Redundancy Protocol (VRRP).
5.7.1 VRRP
The Virtual Router Redundancy Protocol (VRRP) is a computer networking protocol providing
device redundancy. It allows a backup router or switch to automatically take over if the primary
(master) router or switch fails. This increases the availability and reliability of routing paths via
automatic default gateway selections on an IP network.
The protocol achieves this by creation of virtual routers, which are an abstract representation of
multiple routers, i.e. master and backup routers, acting as a group. The default gateway of a
participating host is assigned to the virtual router instead of a physical router. If the physical
router that is routing packets on behalf of the virtual router fails, another physical router is
selected to automatically replace it. The physical router that is forwarding packets at any given
time is called the master router.
In "VRRP" page, there is only one configuration window for Redundancy function. A group of
physical VRRP gateways combined together to play a virtual server with one unique virtual server
ID and one unique virtual server IP address. But these VRRP gateways have their own priority
values to serve as the sequence for backing up the master gateway.
VRRP Configuration
Check the "Enable" box to activate the VRRP function for the gateway. The gateway with VRRP
Index skipping is used to reserve slots for new function insertion, when required.
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