A Route Load Balancing Scenario - D-Link DFL-1660 User Manual

4.4. Route Load Balancing
We first need to define two routes to these two ISPs in the main routing table as shown below:
Route No.
1
2
We will not use the spillover algorithm in this example so the routing metric for both routes should
be the same, in this case a value of 100 is selected.
By using the Destination RLB algorithm we can ensure that clients communicate with a particular
server using the same route and therefore the same source IP address. If NAT was being used for the
client communication, the IP address seen by the server would be WAN1 or WAN2.
In order to flow, any traffic requires both a route and an allowing IP rule. The following rules will
allow traffic to flow to either ISP and will NAT the traffic using the external IP addresses of
interfaces WAN1 and WAN2.
Rule No.
1
1
The service All is used in the above IP rules but this should be further refined to a service or service
group that covers all the traffic that will be allowed to flow.
Example 4.8. Setting Up RLB
Figure 4.7. A Route Load Balancing Scenario
Interface
WAN1
WAN2
Action Src Interface
NAT lan
NAT lan
197
Destination Gateway
all-nets GW1
all-nets GW2
Src Network Dest Interace Dest Network
lannet WAN1
lannet WAN2
Chapter 4. Routing
Metric
100
100
Service
all-nets all_services
all-nets all_services