Configuration support to include GTP TEID field in hash key for load-balancing GTP-U traffic

On an MX Series router with MPCs, when there are multiple equal-cost paths to the same destination for the active route, Junos OS uses a hash algorithm to choose one of the next-hop addresses from the forwarding table when making a forwarding decision. Whenever the set of next hops for a destination changes in any way, the next-hop address is rechosen using the hash algorithm. For GPRS tunneling protocol (GTP)-encapsulated traffic, the tunnel endpoint identifier (TEID) field changes for traffic traversing through peer routers. To implement load balancing for GTP-encapsulated traffic on the user plane (GTP-U), the TEID should be included in the hash key. You can configure GTP hashing on MX Series routers with MPCs and on MX80, to include the TEID field in hash calculations for IPv4 and IPv6 packets. To configure GTP hashing and include the GTP TEID field in hash calculations, configure the gtp-tunnel-end-point-identifier statement at the [edit forwarding-options enhanced-hash-key family] hierarchy level. GTP hashing is supported for both IPv4 and IPv6 packets received for GTP-U traffic at the MPC. For bridging and MPLS packets, GTP hashing is supported for IPv4 and IPv6 packets that are carried as payload for GTP-encapsulated traffic.