Re: tcpdump broken after rh9 2.4.20-27.9 kernel upgrade

From: Robert Brown (eli_at_typhoon.xnet.com)
Date: 12/28/03

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    To: redhat-list@redhat.com
Date: Sun, 28 Dec 2003 03:45:26 -0600 (CST)

    Robert Brown writes:
    > Harry Hoffman writes:
    > > Wait a sec. You are seeing this same behavior on other boxes? Are they all the
    > > same setup? (i.e. RH9->with newest kernel).
    >
    > Same kernel on all boxes: 2.4.20-27.9, as of 12/23/03 or 12/24/03, I
    > forget which.

    Well, egg on my face time again! I now have the 10baseT NIC sniffing
    properly on the hub behind the bridge to the internet. It was not
    working before because of a bad connection. The thing that tipped me
    off was reading over my last reply to this thread "one more time", I
    saw:

        Settings for eth2:
                Supported ports: [ TP MII ]
                Supported link modes: 10baseT/Half 10baseT/Full
                                        100baseT/Half 100baseT/Full
                Supports auto-negotiation: Yes
                Advertised link modes: 10baseT/Half 10baseT/Full
                                        100baseT/Half 100baseT/Full
                Advertised auto-negotiation: Yes
                Speed: 10Mb/s
                Duplex: Half
                Port: MII
                PHYAD: 32
                Transceiver: internal
                Auto-negotiation: on
                Supports Wake-on: pumbg
                Wake-on: d
                Current message level: 0xffffffff (-1)
                Link detected: no

    And then it hit me: the last line says "Link detected: no"! What?
    Why not! Well, I started looking at hardware, and I found that where
    the ethernet cable plugged into the hub, it was not totally pushed in
    all the way. The hub lights should have told me, but either I never
    looked there, or it didn't register at the time. I have no idea how
    it got pulled out. Those things are supposed to latch! Grrr!

    So this proves that promiscuous mode does indeed work, at least on
    that NIC running in that mode.

    I also re-installed the 2.4.20-20.9, 2.4.20-24.9, and 2.4.20-27.9
    kernels. Even when I booted with an earlier kernel, I still could not
    see packets that were not addressed to the NIC or broadcast. I am now
    starting to suspect something funky about those fancy-schmancy
    auto-detecting 10/100baseT hubs! I really wanted a simple 100baseT
    hub, but I could not find any that were affordable. How does it make
    sense to have a full duplex hub anyway? I do not see how that makes
    any sense at all. :-\

    I wish I had a scope... 

    -- 
--------  "And there came a writing to him from Elijah"  [2Ch 21:12]  --------
R. J. Brown III  rj@elilabs.com http://www.elilabs.com/~rj  voice 859 567-7311
Elijah Laboratories Inc.    P. O. Box 166, Warsaw KY 41095    fax 859 567-7311
-----  M o d e l i n g   t h e   M e t h o d s   o f   t h e   M i n d  ------
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