[tcpdump-workers] Multiple Needles in Multiple Haystacks.

Michael Richardson mcr at sandelman.ca
Thu Nov 17 19:25:06 EST 2016


Zaphod Beeblebrox <zbeeble at gmail.com> wrote:
    > Something like "ppp[0:2] == 0x8021" should pull out the IPCP.  Or is
    > that ppp[2:2] ... but neither works.  Some other reading that's hard to
    > find would suggest something like "protochain l2tp and ppp proto
    > 0x8021" ... but that doesn't work either.  I realize that one of
    > ppp[2:2] or ppp[0:2] is going to be equivalent to ppp proto 0x8021, but
    > the part that's not working is relating to the function of protochain.

    > Help?

I'm not sure what is going on here; but filtering is done by libpcap, not by
libpcap itself.  My first thought is to check your byte order!

    > If you're Canadian (I see this list is associated with someone on
    > Ottawa) I can offer 3 months of free DSL... or a whole year if you
    > materially help me fix MPD on FreeBSD.  I'm a fully open-source ISP ...

Yes, I live in Ottawa.

-- 
]               Never tell me the odds!                 | ipv6 mesh networks [ 
]   Michael Richardson, Sandelman Software Works        | network architect  [ 
]     mcr at sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [ 
	


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