Load Balancing in an MPLS Network > Example: Load-Balancing a Network Using INET in the Hash Key

Purpose

The IPv4 address family (INET) provides additional information to identify traffic flows and balance traffic more evenly. You configure the INET or port data on an ingress router. Configuring port data is useful if you are using TCP or UDP. However, it may not be useful to include port data when you are using protocols that are not associated with a Layer 4 port, for example, Layer 2 VPNs, GRE tunneling, or ICMP.

The following network example shows the process for verifying the operation of the hash key configuration of port data as described in Configuring the IPv4 Address Family to Load-Balance LSP Traffic.

Figure 12: INET Network Topology

The network topology in Figure 11 illustrates a router-only network with SONET and Ethernet interfaces that consists of the following components:

• A full-mesh interior BGP (IBGP) topology, using AS 65432
• MPLS and RSVP enabled on all routers
• A send-statics policy on routers R1 and R0 that allows a new route to be advertised into the network
• Four unidirectional LSPs between R1 and R0, and one reverse direction LSP between R0 and R1, which allows for bidirectional traffic
• Load balancing configured on the ingress router R1
• The hash key using port data configured on R1
• Bandwidth configured on the SONET interfaces on R2

In addition, the example network uses Open Shortest Path First (OSPF) as the interior gateway protocol (IGP) with OSPF area 0.0.0.0. An IGP is required for the Constrained Shortest Path First (CSPF) LSP, which is the default for the JUNOS software. Also, the example network uses a policy to create BGP traffic.

The following information is included in this example:

• Verifying the Operation of INET Load Balancing
• Router Configurations for the INET Load-Balanced Network