MPLS transit load balancing

A hashing scheme for enhanced load balancing allows MPLS transit load balancing to include inner headers of different packet types in parallel. With this enhanced load balancing scheme, SLX-OS is capable of load balancing the MPLS packets based on the inner headers like Inner source/destination mac address, Inner IPv4 source/destination address, Inner IPv6 source/destination address, Inner L4 port number if the inner header is IPv4.

Note

Note

MPLS transit load balancing is not supported on Extreme 8820, SLX 9740, SLX 9640, and SLX 9540 devices.

This hashing scheme is supported only with the "Layer 2 Optimized" Tcam profile and when the feature is enabled by default in this profile. When the profile tcam layer2-optimised-1 configuration is activated, the "Error: Operation not supported in the current hardware TCAM profile" message is displayed for the following commands as these functionalities are already taken care of by this enhanced hashing scheme:

Displaying LAG hashing with "Layer 2 Optimized" Tcam profile

Use the show port-channel load-balance command to display the configured parameters for LAG hashing when the profile tcam layer2-optimised-1 configuration is activated. 

device# show port-channel load-balance
Header parameters
        Ethernet Mask: sa-mac da-mac etype vlan
        ip: src-ip dst-ip protocol src-l4-port dst-l4-port
        ipv6: ipv6-src-ip ipv6-dst-ip ipv6-next-hdr ipv6-src-l4-port ipv6-dst-l4-port
        mpls: label1 label2 label3

Hash Settings
        hdr-start:FWD, hdr-count:3, bos-start:0, bos-skip:0, skip-cw:0
        normalize:0, rotate:3, include_src_port:0, Disable: L2 0, ipv4 0, ipv6 0, mpls 0

mpls_speculate: Enabled

Inner Header parameters for MPLS packets
                Ethernet Mask: Selective 64 bits from sa-mac da-mac vlan
                ip: src-ip dst-ip src-l4-port dst-l4-port
                ipv6: ipv6-src-ip ipv6-dst-ip

load-balance-type hash-based

For comparison, the following displays the show port-channel load-balance command output for a non layer 2 optimized profile: 

device# show port-channel load-balance 
Header parameters
        Ethernet Mask: sa-mac da-mac etype vlan 
        ip: src-ip dst-ip protocol src-l4-port dst-l4-port 
        ipv6: ipv6-src-ip ipv6-dst-ip ipv6-next-hdr ipv6-src-l4-port ipv6-dst-l4-port 
        mpls: label1 label2 label3 

Hash Settings
        hdr-start:FWD, hdr-count:1, bos-start:0, bos-skip:0, skip-cw:0 
        normalize:0, rotate:3, include_src_port:0, Disable: L2 0, ipv4 0, ipv6 0, mpls 0
 
mpls_speculate:Enabled

load-balance-type hash-based
9038041-00 Rev AB