MPLS Load Balancing Based on the IP Header and MPLS Labels

Juniper Networks routing platforms can load-balance on a per-packet basis in MPLS. Load balancing can be performed on information in both the IP header and on up to three MPLS labels, providing a more uniform distribution of MPLS traffic to next hops. This feature is enabled on supported platforms by default and requires no configuration.

Note: This feature is only available on M320 and T-series routing platforms with enhanced FPCs.

The following information is extracted from the packet and used to load-balance the MPLS traffic:

• Interface index—24 bits
• MPLS label stack—bits 0 through 23 (the TTL bits are not examined)
• IPv4 header information:
  • Protocol—8 bits
  • Destination address—32 bits
  • Source address—32 bits
  • Source port—16 bits
  • Destination port—16 bits
• IPv6 header information:
  • Next header—8 bits
  • Least significant 4 bytes of destination address
  • Least significant 4 bytes of source address
  • Source port—16 bits
  • Destination port—16 bits

In summary, MPLS load balancing is performed using the following fields:

Interface index + MPLS label+ IP header (IPv4 or IPv6)

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