Allied Telesis AT-WR4500 manual Virtual IP addresses, Simple example of Vrrp fail over

AT-WR4500 Series - IEEE 802.11abgh Outdoor Wireless Routers	251
RouterOS v3 Configuration and User Guide

11.1.3Virtual IP addresses

Submenu level: /ip vrrp address

Property Description

address (IP address) - IP address belongs to the virtual router broadcast (IP address) - broadcasting IP address

interface (name; default: default) - interface, where to put the address on (may be different form the interface this VRRP instance is running on)

default - put this address on the interface the given VRRP instane is working on network (IP address) - IP address of the network

virtual-router(name) - VRRP router's name the address belongs to

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The virtual IP addresses should be the same for each node of a virtual router.

To add a virtual address of 192.168.1.1/24 to the vr1 VRRP router:

[admin@AT-WR4562] ip vrrp> address add address=192.168.1.1/24 \
\... virtual-router=vr1
[admin@AT-WR4562] ip vrrp> address print
Flags: X - disabled, A - active
#	ADDRESS	NETWORK	BROADCAST	INSTANCE INTERFACE
0	192.168.1.1/24	192.168.1.0	192.168.1.255	vr1	default

[admin@AT-WR4562] ip vrrp>

11.1.4A simple example of VRRP fail over

Description

VRRP protocol may be used to make a redundant Internet connection with seamless fail-over. Let us assume that we have 192.168.1.0/24 network and we need to provide highly available Internet connection for it. This network should be NATted (to make fail-over with public IPs, use such dynamic routing protocols as BGP or OSPF together with VRRP). We have connections to two different Internet Service Providers (ISPs), and one of them is preferred (for example, it is cheaper or faster).

Internet

ISP1ISP2

192.168.1.1

LAN

192.168.1.0/24

Figure 35: Simple VRRP fail over example