Amer Networks E5Web GUI - Manual (Page 280)

4.4. Route Load Balancing
Overview
cOS Core provides the option to perform Route Load Balancing (RLB). This is the ability to
distribute traffic over multiple alternate routes using one of a number of distribution algorithms.
The purpose of this feature is to provide the following:
• Balancing of traffic between interfaces in a policy driven fashion.
• To balance simultaneous utilization of multiple Internet links so networks are not dependent
on a single ISP.
• To allow balancing of traffic across multiple VPN tunnels which might be setup over different
physical interfaces.
Enabling RLB
RLB is enabled on a routing table basis and this is done by creating an RLB Instance object. This
object specifies two parameters: a routing table and an RLB algorithm. A table may have only
one Instance object associated with it.
One of the algorithms from the following list can be specified in an RLB Instance object:
• Round Robin
Matching routes are used equally often by successively going to the next matching route.
• Destination
This is an algorithm that is similar to Round Robin but provides destination IP "stickiness" so
that the same destination IP address gets the same route. The algorithm is always used in
conjunction with an ALG.
• Spillover
This uses the next route when specified interface traffic limits are exceeded continuously for
a given time.
Important: Destination must be used with an ALG
The Destination algorithm must be used for traffic that is also subject to a cOS Core
ALG. If either Round Robin or Spillover is used in combination with an ALG, the
behavior may not be as expected.
Disabling RLB
Deleting a routing table's Instance object has the effect of switching off RLB for that table.
RLB Operation
When RLB is enabled for a routing table through an RLB Instance object, the sequence of
Chapter 4: Routing
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