40. NULL Poll Mode Driver

NULL PMD is a simple virtual driver mainly for testing. It always returns success for all packets for Rx/Tx.

On Rx it returns requested number of empty packets (all zero). On Tx it just frees all sent packets.

40.1. Usage

./<build_dir>/app/dpdk-testpmd -l 0-3 -n 4 --vdev net_null0 --vdev net_null1 -- -i

40.2. Runtime Config Options

  • copy [optional, default disabled]

It copies data of the packet before Rx/Tx. For Rx it uses another empty dummy mbuf for this.

./<build_dir>/app/dpdk-testpmd -l 0-3 -n 4 --vdev "net_null0,copy=1" -- -i
  • size [optional, default=64 bytes]

Custom packet length value to use.r If copy is enabled, this is the length of copy operation.

./<build_dir>/app/dpdk-testpmd -l 0-3 -n 4 --vdev "net_null0,size=256" -- -i
  • no-rx [optional, default disabled]

Makes PMD more like /dev/null. On Rx no packets received, on Tx all packets are freed. This option can’t co-exist with copy option.