Re: Any changes in Multicast code between 2.4.20 and 2.4.22/23 ?

From: Martin Knoblauch (knobi_at_knobisoft.de)
Date: 01/06/04

  • Next message: David Lang: "Re: 2.6.0 performance problems"
    Date:	Mon, 5 Jan 2004 18:21:22 -0800 (PST)
    To: David Stevens <dlstevens@us.ibm.com>
    
    
    

    --- David Stevens <dlstevens@us.ibm.com> wrote:
    >
    >
    Hi David,
     
    >
    >
    > Martin,
    > If you have other hosts on that network that have sent IGMP
    > reports,
    > then
    > the reporter flag will be cleared-- only one member on a network
    > needs to
    > send
    > reports. That doesn't prevent the host from receiving multicasts--
    > presence
    > in
    > /proc/net/igmp indicates it did join the group.

    OK. I just wondered, because all hosts running the 2.4.20-18.7smp
    kernel (RH7.3 errata) show the "1" in the reporter field, while all
    hosts running 2.4.22/2.4.23 (vanilla plus NFS fixes from Trond) show
    "0".

    > Please send me some details about your set-up and I may be able
    > to
    > help.

     We are running 21 HP/DL380G3.Each has two internal Broadcom NICs. The
    second one (eth1) is used for the Ganglia multicast.

     The kernels are 2.4.22 and 2.4.23 (now .24) with some NFS patches. In
    the case of 2.4.24 those are:

    01-posix_race
    02-fix_commit
    03-fix_osx
    04-fix_lockd3
    06-fix_unlink
    07_seekdir

     from http://www.fys.uio.no/~trondmy/src/Linux-2.4.x/2.4.23-rc1 None of
    those looks like it does something to multicasts. In the worst case I
    could try to run with plain 2.4.22/23, but that would have to ait until
    Wednesday.

     The kernel-config file is included.

    > First, are the sender and receiver on the same network, or are
    > you
    > using a multicast router?

     No. All systems are on the same network.

    > Second, can you send me a tcpdump-format packet trace
    > (preferrably
    > only the multicast traffic, and as small as you can make it)?

     What exactely do you want to see? On which box should I run tcpdump?
    Which options (I'm not that deep into network debugging :-)?

    > You mentioned tg3-- have you tried this with other hardware
    > that
    > worked?
    >

     The tg3 works with the 2.4.20-18.7smp (and earlier) kernels. It just
    does not work with 2.4.22/23 (did not check 2.4.21).

     Unfortunatelly I have no other boxes to test with. I only can say that
    Ganglia never failed in this particular way on any setup.

    Thanks
    Martin

    =====
    ------------------------------------------------------
    Martin Knoblauch
    email: k n o b i AT knobisoft DOT de
    www: http://www.knobisoft.de

    
    

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/



  • Next message: David Lang: "Re: 2.6.0 performance problems"

    Relevant Pages

    • Re: Any changes in Multicast code between 2.4.20 and 2.4.22/23 ?
      ... Can you look on the adjacent multicast routerand see if your host is ... listed as a group member? ... >> If you have other hosts on that network that have sent IGMP ...
      (Linux-Kernel)
    • multicast at the data layer (layer 2) non-flooding ?
      ... I am looking into multicast in a private network at the data layer. ... Basically what I need is multicast which is not flooded within a LAN. ... Therefore, if there are 5 hosts connected to a router, I would like to ...
      (comp.os.linux.networking)
    • Re: Heavyweight Network Mapping Tools
      ... multiple threads so as not to adversely effect any individual sub network ... The goals for the OPTE project are slightly ... >> Hosts alive through ICMP ... I was loooking more for the vulnerability scanning approach without ...
      (Pen-Test)
    • Re: Scanning Class A network
      ... > within the network to identify hosts and ports exposed to the ... ICMP was not allowed in the network ... ports for all IPs. ... Cross site scripting and other web attacks before hackers do! ...
      (Pen-Test)
    • Very slow SMB performance on one interface of a multi-homed server
      ... one interface and a private gigabit network on the other. ... Of the seven hosts, four are Windows 2000 server and three are XP. ... Connections using the office LAN and, ...
      (microsoft.public.windows.server.networking)