Proroute GEM420 4G M2M Router
GEM420 User Manual
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11.
IPSec Pre-shared Key:
This option is only for DMVPN spoke function. If you
enable DMVPN spoke feature, you need to enter same pre-shared key of your
existed IPSec tunnel.
12. Tunnel:
Enable or disable this GRE tunnel.
3.2.4 Redundancy
3.2.4.1 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.
