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  1. #1

    Destination unreachable (Host administratively prohibited


    I have a program which send TCP packets from laptop A to laptop B (there is a laptop C which acts as relay, and B send packets to C(192.168.0.100) and then A sends response packets to B with spoofed IP. both A, B and C are in the same WLAN), and I capture packets on A (interface:wlan0), the pcap file is: send.pcap :: Free File Hosting - File Dropper: File Host for Mp3, Videos, Music, Documents.

    also I capture packets on B(interface:wlan0), the pcap file is: client3.pcap :: Free File Hosting - File Dropper: File Host for Mp3, Videos, Music, Documents.

    I notice the NO.8 - NO.12 packets in A pcap file, namely the TCP packet with seq number 7318 - 11698 are absent in B pcap file. Instead,there are 3 ICMP packets in B pcap file, which says **Destination unreachable (Host administratively prohibited)**. These ICMP packets are actually sent by C to B. I guess that these ICMP packets and IP-spoofing TCP packets from A arrive at B at the same time, and the TCP/IP stack reject the TCP packets because they receive these ICMP packets, am I right?

    C sends these ICMP packets because it receives unwanted/unexected TCP packets from B, what can I do to stop C from sending these ICMP packets when it receives unexpected TCP packets?
    Last edited by esolve; 10-28-2015 at 03:26 PM.

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