Hardware Large Receive Offload (HW LRO)

Large Receive Offload (LRO) increases inbound throughput of high-bandwidth network connections by reducing CPU overhead. It works by aggregating multiple incoming packets from a single stream into a larger buffer before they are passed higher up the networking stack, thus reducing the number of packets that have to be processed.

In order to turn on the LRO device, run: 

#> ifconfig mce<x> lro

In order to turn off the LRO device, run: 

#> ifconfig mce<x> -lro

When the LRO device is on, HW LRO can be turned on. HW LRO is off by default. 

In order to turn on HW LRO run: 

#> sysctl dev.mce.<N>.conf.hw_lro=1

In order to turn off HW LRO run: 

#> sysctl dev.mce.<N>.conf.hw_lro=0

Last updated: September 07, 2020