Allied Telesis AT-WR4500 manual Property Description

AT-WR4500 Series - IEEE 802.11abgh Outdoor Wireless Routers	155
RouterOS v3 Configuration and User Guide

Description

To provide a proper failover, you should specify link-monitoringparameter. It can be:

•MII (Media Independent Interface) type1 or type2 - Media Independent Interface is an abstract layer between the operating system and the NIC which detects whether the link is running (it performs also other functions, but in our case this is the most important).

•ARP - Address Resolution Protocol periodically (for arp-intervaltime) checks the link status.

link-monitoringis used to check whether the link is up or not.

Property Description

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

disabled - the interface will not use ARP enabled - the interface will use ARP

proxy-arp- the interface will use the ARP proxy feature

reply-only- the interface will only reply to the requests originated to its own IP addresses. Neighbour MAC addresses will be resolved using /ip arp statically set table only

arp-interval(time; default: 00:00:00.100) - time in milliseconds which defines how often to monitor ARP requests

arp-ip-targets(IP address; default: "") - IP target address which will be monitored if link-monitoringis set to arp. You can specify multiple IP addresses, separated by comma

down-delay(time; default: 00:00:00) - if a link failure has been detected, bonding interface is disabled for down-delaytime. Value should be a multiple of mii-interval

lacp-rate(1sec 30secs; default: 30secs) - Link Aggregation Control Protocol rate specifies how often to exchange with LACPDUs between bonding peer. Used to determine whether link is up or other changes have occured in the network. LACP tries to adapt to these changes providing failover. link-monitoring(arp mii-type1 mii-type2 none; default: none) - method to use for monitoring the link (whether it is up or down)

arp - uses Address Resolution Protocol to determine whether the remote interface is reachable mii-type1- uses Media Independent Interface type1 to determine link status. Link status determenation relies on the device driver. If bonding shows that the link status is up, when it should not be, then it means that this card don't support this possibility.

mii-type2- uses MII type2 to determine link status (used if mii-type1is not supported by the NIC) none - no method for link monitoring is used. If a link fails, it is not considered as down (but no traffic passes through it, thus).

mac-address(read-only: MAC address) - MAC address of the bonding interface

mii-interval(time; default: 00:00:00.100) - how often to monitor the link for failures (parameter used only if link-monitoringis mii-type1or mii-type2)

mode (802.3ad active-backup balance-alb balance-rr balance-tlb balance-xor broadcast; default: balance-rr) - interface bonding mode. Can be one of:

802.3ad - IEEE 802.3ad dynamic link aggregation. In this mode, the interfaces are aggregated in a group where each slave shares the same speed. If you use a switch between 2 bonding routers, be sure that this switch supports IEEE 802.3ad standard. Provides fault tolerance and load balancing.

active-backup- provides link backup. Only one slave can be active at a time. Another slave becomes active only, if first one fails.

balance-alb- adaptive load balancing. It includes balance-tlband received traffic is also balanced. Device driver should support for setting the mac address, then it is active. Otherwise balance-albdoesn't work. No special switch is required.

balance-rr- round-robin load balancing. Slaves in bonding interface will transmit and receive data in sequential order. Provides load balancing and fault tolerance.

balance-tlb- Outgoing traffic is distributed according to the current load on each slave. Incoming traffic is received by the current slave. If receiving slave fails, then another slave takes the MAC address of the failed slave. Doesn't require any special switch support.

balance-xor- Use XOR policy for transmit. Provides only failover (in very good quality), but not load balancing, yet.

broadcast - Broadcasts the same data on all interfaces at once. This provides fault tolerance but slows down traffic throughput on some slow machines.

mtu (integer: 68..1500; default: 1500) - Maximum Transmit Unit in bytes