I am trying to understand DCTCP behavior. For that I am using RED queue discipline on switch port. I am generating traffic using iperf3 for 30 seconds. To capture the packets i am using tcpdump. However the tcpdump file is too large.
So, I wish to extract the packets that have been marked with ECN. Can someone please suggest a way so that I can filter only those packets that have ECN bit set in TCP headers ? Thanks in advance.