Information Technology Reference
In-Depth Information
Case Study: Load Balancing in a Multihoming
Environment
This case study examines the process of balancing traffic in a multihoming environment. A
standard enterprise DMZ network is presented, with a focus on the Internet connectivity
aspects and defining traffic flow policies. The security aspects of deploying Internet
connectivity are outside the scope of this discussion.
Scenario Overview
The enterprise is currently single-homed, with no redundancy. The enterprise does not have
its own ASN and uses a single static default route pointing toward the upstream ISP.
Internet connectivity has been identified as a mission-critical service. A new multihomed Inter-
net connectivity design must be deployed that provides fault-tolerant service. The new con-
nectivity design will make use of multiple border routers with diverse upstream providers.
This new design is shown in Figure 6-10.
Figure 6-10
Multihomed Enterprise Network Scenario
Internet
Provider B (AS 200)
Provider A (AS 100)
OC3
DS3
DS3
R2
R3
Enterprise (AS 300)
R1
