This command is used to configure the "default" hash algorithm used to choose a gateway when hardware forwards an IPv4 or IPv6 unicast packet to a route with multiple equal-cost multipath gateways.
For information about configuring the custom hash method, see the command configure iproute sharing hash-method custom.
The values within the IP unicast packet that are considered in the hash calculation depend on the setting of another command, configure forwarding sharing [L3 | L3_L4]. With the default, L3_L4, the hash calculation includes Source and Destination IP addresses, and the Source and Destination Layer 4 Port numbers. Or, if configure forwarding sharing L3 is configured, the hash calculation only includes Source and Destination IP addresses. The distribution of packets among multiple gateways based on the IP Route Sharing lower or upper hash algorithm will depend on network traffic. The command will not result in traffic loss and takes effect immediately.
| iproute | IP routing module. |
| sharing | Configure settings for equal cost multipath routing";capability="route_sharing. |
| hash-method | Configures hardware forwarding hash method used to select among ECMP gateways for an IPv4 or IPv6 destination. |
| default | Default method for ECMP hardware hash calculation. For information about configuring the custom hash method, see the configure iproute sharing hash-method custom {hash-algorithm [xor | crc-16 | crc-32 [lower | upper]]} command. |
| hash-algorithm | Configure hardware forwarding hash algorithm used to select among ECMP gateways for an IPv4 or IPv6 destination";capability="pib". |
| crc | Cyclic Redundancy Check (CRC). |
| lower | Lower bits of CRC32 hash calculation of source and destination packet criteria, used to select an ECMP gateway (Default). |
| upper | Upper bits of CRC32 hash calculation. May improve distribution when source and destination IP and ports do not vary much. |
Use this command to configure the hash algorithm used to choose a gateway when hardware forwards an IPv4 or IPv6 unicast packet to a route with multiple equal-cost multipath gateways. The values within the IP unicast packet that are considered in the hash calculation depend on the setting of another command, configure forwarding sharing [L3 | L3_L4]. With the default, L3_L4, the hash calculation includes Source and Destination IP addresses, and the Source and Destination Layer 4 Port numbers. Or, if configure forwarding sharing L3 is configured, the hash calculation only includes Source and Destination IP addresses. The distribution of packets among multiple gateways based on the IP Route Sharing lower or upper hash algorithm will depend on network traffic. The command will not result in traffic loss and takes effect immediately.
# configure iproute sharing hash-algorithm upper
This command was first available in ExtremeXOS 15.4.
This command is available on ExtremeSwitching X435, X440-G2, X450-G2, X460-G2, X465, X590, X620, and X695 series switches.