l2perf

l2perf is a networking tool for Linux that aims to be similar to iperf UDP mode but for layer 2 (data link) networking. It utilizes the pnet library for data link layer communication to generate and receive traffic.

Use Cases

Although it doesn't sound very useful, it may come in handy if you just need to generate some random traffic over a network to create a test case you need. As long as there is a valid MAC destination address on the receiving end it shouldn't require any prior connection or IP layer setup just to generate traffic. There may be valid cases without an existing destination MAC address but for most cases packets will likely get dropped on the other end of the link.

If you run the tool also on the receiving end, it can be used to analyze achievable bandwidth and drop rates in a similar way to iperf UDP.

Usage

The tool allows you to configure the network interface, payload size, ethertype, test duration and the target bandwidth. See --help for additional info.

Example Run

An example test output from a test with a laptop using Intel 802.11ac WiFi card to a receiving Raspberry Pi 4 connected to a WiFi router over Ethernet.

Tx Side

# ./l2perf  -i wlan0 -t 10 -b 350 dc:a6:32:01:01:01
Sec: 0.00-1.01, Sent: 27938 pkts, Rate: 332.59 Mbps
Sec: 1.01-2.01, Sent: 30537 pkts, Rate: 366.35 Mbps
Sec: 2.01-3.01, Sent: 28096 pkts, Rate: 337.15 Mbps
Sec: 3.01-4.01, Sent: 29490 pkts, Rate: 353.72 Mbps
Sec: 4.01-5.01, Sent: 29682 pkts, Rate: 356.18 Mbps
Sec: 5.01-6.01, Sent: 29501 pkts, Rate: 354.00 Mbps
Sec: 6.01-7.01, Sent: 27806 pkts, Rate: 333.18 Mbps
Sec: 7.01-8.01, Sent: 29324 pkts, Rate: 351.82 Mbps
Sec: 8.01-9.01, Sent: 29234 pkts, Rate: 350.67 Mbps
Summary:
Sec: 0.00-10.00, Sent: 291534 pkts, Rate: 349.82 Mbps

Rx Side

# ./l2perf  -i eth0 -r
Accepting Ether Type 7380...

New incoming traffic:
Sec: 0.00-1.01, Recv: 27938/27938 pkts, Dropped: 0.00%, Rate: 332.70 Mbps
Sec: 1.01-2.01, Recv: 30247/30530 pkts, Dropped: 0.93%, Rate: 362.96 Mbps
Sec: 2.01-3.01, Recv: 27241/28075 pkts, Dropped: 2.97%, Rate: 326.89 Mbps
Sec: 3.01-4.01, Recv: 29413/29494 pkts, Dropped: 0.27%, Rate: 352.95 Mbps
Sec: 4.01-5.01, Recv: 29599/29663 pkts, Dropped: 0.22%, Rate: 355.12 Mbps
Sec: 5.01-6.01, Recv: 29558/29558 pkts, Dropped: 0.00%, Rate: 354.69 Mbps
Sec: 6.01-7.01, Recv: 27791/27792 pkts, Dropped: 0.00%, Rate: 333.19 Mbps
Sec: 7.01-8.01, Recv: 29303/29303 pkts, Dropped: 0.00%, Rate: 351.63 Mbps
Sec: 8.01-9.01, Recv: 29231/29231 pkts, Dropped: 0.00%, Rate: 350.68 Mbps
Summary:
Sec: 0.00-10.00, Recv: 290266/291534 pkts, Dropped: 0.43%, Rate: 348.31 Mbps