Vrrp/Hivrrp - Hirschmann Power MICE User Manual

VRRP/HiVRRP

5 VRRP/HiVRRP
Terminal devices usually give you the option of entering a default gateway for
transmitting data packets in external subnetworks. Here the term "Gateway"
applies to a router by means of which the terminal device can communicate
in other subnetworks.
If this router fails, the terminal device cannot send any more data to external
subnetworks.
In this case, the Virtual Router Redundancy Protocol (VRRP) provides assis-
tance.
VRRP is a type of "gateway redundancy". VRRP describes a process that
groups multiple routers into one virtual router. Terminal devices always ad-
dress the virtual router, and VRRP ensures that a physical router belonging
to the virtual router takes over the data transmission.
Even if a physical router fails, VRRP ensures that another physical router
takes over the distribution tasks as part of the virtual router.
VRRP has typical switching times of 3 to 4 seconds when a physical router
fails.
In many cases, such as Voice over IP, Video over IP, industrial controllers,
etc., these long switching times are not acceptable.
The Hirschmann company has further developed the VRRP into the
Hirschmann Virtual Router Redundancy Protocol (HiVRRP).
With the appropriate configuration, HiVRRP guarantees maximum switching
times of 400 milliseconds.
Thanks to this guaranteed switching time, HiVRRP enables the use of "gate-
way redundancy" in time-critical applications. Even in tunnel controllers that
require switching times of less than one second, the user can improve the
network availability with this form of "gateway redundancy".
Routing L3E
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Release 4.2 08/08