Load Balancing

Introduction

Load Balancing is methology with aim to spread traffic across multiple links to get better links usage. This can be done one per-packet or per-connection basis.

Method	Per-connection	Per-packet
Firewall marking	Yes	Yes
ECMP	Yes	No
PCC	Yes	No
Nth	Yes	Yes
Bonding	No	Yes
OSPF	Yes	No
BGP	Yes	No

Methods

Firewall marking

This method use firewall packet marking to select one from multiple gateways.

• Per-Traffic Load Balancing
• Load Balancing over Multiple Gateways
• Manual:Load balancing multiple same subnet links
• Improved Load Balancing over Multiple Gateways
• Improved Load Balancing over Multiple Gateways Failover Script

ECMP (Equal Cost Multi-Path)

This method use multiple gateway with same cost.

• ECMP load balancing with masquerade
• ECMP Failover Script
• Manual:IP/Route#Multipath (ECMP) routes

PCC (Per Connection Classifier)

• Manual:PCC

Nth

• NTH load balancing with masquerade
• NTH load balancing with masquerade (another approach)
• Nth
• Manual:NTH in RouterOS 3.x

Bonding

Can combine multiple links to get link with higher speed.

• Manual:Interface/Bonding
• Bonding Examples

OSPF

Two or more links are setup with dynamic routing protocol OSPF with equal cost. Then equal multipath routing is used.

• #ECMP
• Manual:Routing/OSPF
• Manual:Route Selection Algorithm in RouterOS#Load balancing and dynamic routing protocols

BGP

• Manual:BGP Load Balancing with two interfaces
• Manual:Simple BGP Multihoming#Load_sharing_setup

External links

• wikipedia:Load balancing (computing)