I have tested this on kernel 4.4.0 (in Xenial) and I don't think the fix that went into 3.19 fixed the entire issue.
My understanding is that since nmap uses a relatively long pcap_select() timeout, and the packet buffers in the kernel aren't filling up fast enough, the packet loss can still be seen. I see that you have worked around this in nmap by disabling TPACKET_v3: https://github.com/nmap/nmap/commit/83b9c4c939094e673705b7c270533708853891f0 I noticed that another project (which I found linked to the libpcap bug) worked around this issue by using libpcap's immediate_mode: https://github.com/teclo/flow- disruptor/commit/3376d049fc5280aedccc42fc6e090c32c0c4a128 Would you consider trying this same workaround in nmap, since it seems more general than forcing TPACKET_V3 to be disabled? (That is, only users who compile nmap from source and use "./configure --with- libpcap=included" can currently use the workaround.) ** Bug watch added: github.com/nmap/nmap/issues #34 https://github.com/nmap/nmap/issues/34 ** Also affects: linux via https://github.com/nmap/nmap/issues/34 Importance: Unknown Status: Unknown ** Project changed: linux => nmap ** Bug watch added: github.com/the-tcpdump-group/libpcap/issues #380 https://github.com/the-tcpdump-group/libpcap/issues/380 ** Also affects: tcpdump via https://github.com/the-tcpdump-group/libpcap/issues/380 Importance: Unknown Status: Unknown -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1457472 Title: TPACKET_V3 in Linux before 3.19 causes packet loss in libpcap To manage notifications about this bug go to: https://bugs.launchpad.net/nmap/+bug/1457472/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs