I have two Linux machines connected to each other by 10G NIC Card, on one machine I have a pcap file where i am sending the packets using libpcap in C Code based on the packet interval compared to first packet present in the pcap file, then i am doing tcpdump for the incoming packets on the different machine into a pcap file, now the packet interval time is as expected to original at the start of few 100 packets, then the difference starts increasing linearly, any idea why? I also did tcpdump on the transmitting side there the time drift is not seen.
Sending side pcap file comparison enter image description here
capture side pcap file comparison enter image description here
Expected was acceptable difference, but getting linear drift