Allied Telesis AT-WR4500 manual Property Description

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

other configuration) active. A backup instance is not 'running', so all the settings attached to that interface is inactive.

Property Description

arp (disabled enabled proxy-arp reply-only; default: enabled) - Address Resolution Protocol

authentication (none simple ah; default: none) - authentication method to use for VRRP advertisement packets

none - no authentication simple - plain text authentication

ah - Authentication Header using HMAC-MD5-96 algorithm backup (read-only: flag) - whether the instance is in the backup state interface (name) - interface name the instance is running on

interval (integer: 1..255; default: 1) - VRRP update interval in seconds. Defines how frequently the master of the given cluster sends VRRP advertisement packets

mac-address(MAC address) - MAC address of the VRRP instance. According to the RFC, any VRRP instance should have its unique MAC address

master (read-only: flag) - whether the instance is in the master state

mtu (integer; default: 1500) - Maximum Transmission Unit name (name) - assigned name of the VRRP instance

on-backup(name; default: "") - script to execute when the node switch to backup state

on-master(name; default: "") - script to execute when the node switch to master state

password (text; default: "") - password required for authentication depending on method used can be ignored (if no authentication used), 8-character long text string (for plain-text authentication) or 16- character long text string (128-bit key required for AH authentication)

preemption-mode(yes no; default: yes) - whether preemption mode is enabled

no - a backup node will not be elected to be a master until the current master fail even if the backup node has higher priority than the current master

yes - the master node always has the priority

priority (integer: 1..255; default: 100) - priority of the current node (higher values mean higher priority) 255 - RFC requires that the router that owns the IP addresses assigned to this instance had the priority of 255

vrid (integer: 0..255; default: 1) - Virtual Router Identifier (must be unique on one interface)

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All the nodes of one cluster must have the same vrid, interval, preemption-mode, authentication and password.

To add a VRRP instance on ether1 interface, forming (because priority is 255) a virtual router with vrid of 1:

[admin@AT-WR4562] ip vrrp> add interface=ether1 vrid=1 priority=255

[admin@AT-WR4562] ip vrrp> print

Flags: X - disabled, I - invalid, M - master, B - backup

0I name="vr1" interface=ether1 vrid=1 priority=255 interval=1 preemption-mode=yes authentication=none password="" on-backup="" on-master=""

[admin@AT-WR4562] ip vrrp>

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Note that the instance is active at once. This is because it has the priority of 255. The instance would wait in backup mode for a new master election process to complete in its favour before assuming the master role otherwise. This also means that there must not be other VRRP routers with the maximal priority