User's Manual

Redundancy (VRRP)

Virtual Router Redundancy Protocol (VRRP) is a non-proprietary redundancy protocol designed to increase the availability of

the default gateway servicing hosts on the same subnet. This increased reliability is achieved by advertising a “virtual router” (an

abstract representation of master and backup routers acting as a group) as a default gateway to the host(s) instead of one

physical router. Two or more physical routers are then configured to stand for the virtual router, with only one doing the actual

routing at any given time. If the current physical router that is routing the data on behalf of the virtual router fails, an

arrangement is made for another physical router to automatically replace it. The physical router that is currently forwarding data

on behalf of the virtual router is called the master router.

Master routers have a priority of 255 and backup router(s) can have a priority between 1 and 254.

A virtual router must use 00-00-5E-00-01-XX as its (MAC) address. The last byte of the address (XX) is the Virtual Router

Identifier (VRID), which is different for each virtual router in the network. This address is used by only one physical router at a

time, and is the only way that other physical routers can identify the master router within a virtual router.

Figure 41 - VRRP configuration

To configure VRRP, configure multiple devices as follows and connect them all via an Ethernet network switch to downstream

devices.

1. Click the Redundancy (VRRP) toggle key to activate VRRP.

2. In the Virtual ID field, enter an ID between 1 and 255. This is the VRRP ID which is different for each virtual router on

the network.

3. In the Router Priority field, enter a value for the priority – a higher value is a higher priority.

4. The Virtual IP Address field is used to specify the VRRP IP address – this is the virtual IP address that both virtual

routers share.

5. Click the Save button to save the new settings.

Note: Configuring VRRP changes the MAC address of the Ethernet port and therefore if you want to resume with the

web configuration you must use the new IP address (VRRP IP) or on a command prompt type:

arp –d <ip address>

(i.e.

arp –d 192.168.1.1)

to clear the arp cache.(old MAC address).

NetComm Wireless CDMA M2M Router