Vrrp - Hirschmann Power MICE User Manual

VRRP/HiVRRP

5.1 VRRP

All the routers within a network on which VRRP is active specify among them-
selves which router is to be the master. This router contains the IP and MAC
address of the virtual router. All the devices in the network that have entered
this virtual IP address as the default gateway use the master as the default
gateway.
10.0.1.13
10.0.1.12
Default Gateway
10.0.1.254
10.0.1.11
10.0.1.10
Figure 13: Illustration of the virtual router
If the master fails, then the remaining routers use the VRRP to specify a new
master. This router then takes over the IP and MAC address of the virtual
router. Thus the devices find their route via their default gateway, as before.
The devices always only see the master with the virtual MAC and IP address-
es, regardless of which router is actually behind this virtual address.
The virtual router IP address is assigned by the administrator.
The VRRP specifies the virtual MAC address with:
00:00:5e:00:01:<VRID>.
The first 5 octets form the fixed part in accordance with RFC 2338.
The last octet is the virtual router ID (VRID). It is a number between 1 and
255. On the basis of this, the administrator can define 255 virtual routers with-
in a network.
42
Redundancy
through VRRP
10.0.1.1
A
VR
10.0.1.254
B
10.0.1.2
5.1 VRRP
Routing L3E
Release 4.2 08/08