iptables drop packet by hex string match

Posted by Flint on Server Fault See other posts from Server Fault or by Flint
Published on 2012-07-02T14:47:23Z Indexed on 2012/07/02 15:17 UTC
Read the original article Hit count: 310

Filed under:

iptables

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tcpdump

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packet

I got this packet captured with tcpdump but I'm not sure how to use the --hex-string param to match the packet. Can someone show me how to do it?

11:18:26.614537 IP (tos 0x0, ttl 17, id 19245, offset 0, flags [DF], proto UDP (17), length 37)
    x.x.187.207.1234 > x.x.152.202.6543: [no cksum] UDP, length 9
        0x0000:  f46d 0425 b202 000a b853 22cc 0800 4500  .m.%.....S"...E.
        0x0010:  0025 4b2d 4000 1111 0442 5ebe bbcf 6701  .%[email protected]^...g.
        0x0020:  98ca 697d 6989 0011 0000 ffff ffff 5630  ..i}i.........V0
        0x0030:  3230 3300 0000 0000 0000 0000            203.........

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