pktgen traffic activity on dpdk interfaces

Question

I have two physical machines (Host 1 and Host 2) with two DPDK configured 10G Intel NICs (port 0 and port 1) on each. Port 0 and port 1 of both machines are connected with each other directly. On Host 2, l3fwd is running to enable traffic forwarding between dpdk NICs. On Host 1, pktgen is running as packet generator.

As I start pktgen, both ports start receiving traffic (see the attachment), which I am unable to figure out from where. It keeps happening even after passing "stop " or changing Mac addressed and ip addresses.

Please advice.

Answer 1

If LLDP protocol is enabled by default (Intel X710) you will be getting discovery packets once DPDK application is started. I believe this is what you are seeing on pkt-gen as spurious packet.

I modified the primary DPDK application to invoke rte_pdump_init and ran dpdk-pdump utility in another console.

# tcpdump -r /tmp/rx.pcap
reading from file /tmp/rx.pcap, link-type EN10MB (Ethernet)
18:40:29.405996 LLDP, length 69
18:40:30.402803 LLDP, length 69
18:40:31.399615 LLDP, length 69
18:40:32.396427 LLDP, length 69