ng_tee, right2left, et al

From: Ceri Davies (ceri_at_submonkey.net)
Date: 10/03/05

  • Next message: Gleb Smirnoff: "Re: ng_tee, right2left, et al" 
    Date: Mon, 3 Oct 2005 14:07:31 +0100
To: net@FreeBSD.org

    I've discovered an application for which netgraph looks perfect, so have
    just started reading the docs whilst paying proper attention. I started
    out with ng_tee as it looked the simplest, but I've found myself
    confused already.

    The manpage for ng_tee says:

     Tee nodes have four hooks, right, left, right2left, and left2right.
     All data received on right is sent unmodified to both hooks left and
     right2left. Similarly, all data received on left is sent unmodified
     to both right and left2right.

     Packets may also be received on right2left and left2right; if so, they
     are forwarded unchanged out hooks right and left, respectively.

    Now that last bit looked wrong to me; I would have though that a packet
    received on right2left would be copied to left. Checking the code shows
    that the manpage is correct, though Archie Cobbs' article at
    http://ezine.daemonnews.org/200003/netgraph.html says that the opposite
    is true.

    Is this behaviour that was changed for some reason, or has it always
    been "wrong"?

    Ceri 

    -- 
Only two things are infinite, the universe and human stupidity, and I'm
not sure about the former.			  -- Einstein (attrib.)

  • Next message: Gleb Smirnoff: "Re: ng_tee, right2left, et al"

    Relevant Pages

    • Re: ng_tee, right2left, et al
      ... C> Tee nodes have four hooks, right, left, right2left, and left2right. ... What is said here is not true nowadays. ...
      (freebsd-net)
    • Re: Bridging and port mirroring
      ... Tee nodes have four hooks, right, left, right2left, and ... All data received on right is sent unmodified to both hooks ... left and right2left. ... ified to both right and left2right." ...
      (freebsd-questions)
    • Re: ng_tee, right2left, et al
      ... > C> are forwarded unchanged out hooks right and left, ... > C> received on right2left would be copied to left. ... It just seems to me that packets leaving left2right would go to right, ... I found it confusing. ...
      (freebsd-net)