Intel Dpdk L2 Forwarding; Figure 31: The Concept Of L2 Forwarding - Advantech FWA-T011 Getting Started Manual

Step 12: Reset the shell environment
# reset
Step 13: Use 'dpdk-devbind-atom-latest.py -b <PRE DRIVER> <PFA>' command to bind the
specified devices (which are bound to igb_uio driver) to the previous kernel driver:
#dpdk-devbind-atom-latest.py -b <PRE DRIVER> < PORT 1 PFA >
#dpdk-devbind-atom-latest.py -b <PRE DRIVER> < PORT 2 PFA >

3.9.3 Intel DPDK L2 Forwarding

Given that Intel DPDK packet generator is well-sophisticated after previous section was
introduced, the L2FWD sample application performs Layer 2 forwarding for each packet that
is received on an RX_PORT. The destination port is the adjacent port from the enabled port
mask. For example, assuming an N-ports platform with configured port mask 0xf for enabling
L2 forwarding, then it means the first four ports are enabled with L2 forwarding.
Furthermore, port 1 and port 2 forward packets to each other, and port 3 and port 4 forward
packets to each other. Please refer to the following figure for L2 forwarding concept.

Figure 31: the Concept of L2 Forwarding

This section will introduce how to run DPDK l2fwd application with DPDK packet generator
(Pktgen) to perform a 4 ports loopback test. In our example (i.e.Figure 3237), Port 1 and
Port 3 have been connected through one patch cable; likewisely, Port 2 and Port 4 have
been connected through another patch cable. Considering the one-way (half-duplex) packet
flow, the flow will be like this: Pktgen -> Port 1 -> Port 3 -> Port 4 -> Port 2 -> Pktgen. In a
similar way, the opposite packet flow will be: Pktgen -> Port 2 -> Port 4 -> Port 3 -> Port1 ->
Pktgen.
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