Load balancing is a powerful tool for engineering traffic across a
network. This memo suggests ways of improving load balancing across
MPLS networks using the concept of "entropy labels". It defines the
concept, describes why entropy labels are useful, enumerates
properties of entropy labels that allow maximal benefit, and shows
how they can be signaled and used for various applications. This
document updates RFCs 3031, 3107, 3209, and 5036. [STANDARDS-TRACK]