Re: [LARTC] speed problem

["Martin A. Brown" <mabrown-lartc@securepipe.com>]

Vishal,

 : > the first thing i'd like to check is if the ethernet cards are running
 : > in full- or half-duplex mode. AFAIK running one card in half-duplex mode
 : > and the other trying to force full-duplex mode can lead to lots of
 : > collisions, so this could be a reason for slow speed.

I agree with Ulrich, and apparently that may have been your problem.

 : thanks for the reply, i found that there are collission when i use a
 : hub in between, How do i make sure that both the ethernet cards are
 : running in half or full duplex mode, how do i check if weathere an
 : ethernet is in half or full duplex mode

You may find that one of the following tools helps you to determine what
your ethernet card has negotiated with its peer:

  - ethtool ( the tool which will probably continue to be maintained and
             supported under linux )
    http://www.gnu.org/directory/sysadmin/Monitor/ethtool.html

  - mii-diag, aka mii-tool, ( one of these two is usually available on
    common distributions available today )
    http://freshmeat.net/projects/mii-diag/

-Martin

Here's some example output from mii-diag and mii-tool:

# mii-tool --help
usage: mii-tool [-VvRrwl] [-A media,... | -F media] [interface ...]
       -V, --version               display version information
       -v, --verbose               more verbose output
       -R, --reset                 reset MII to poweron state
       -r, --restart               restart autonegotiation
       -w, --watch                 monitor for link status changes
       -l, --log                   with -w, write events to syslog
       -A, --advertise=media,...   advertise only specified media
       -F, --force=media           force specified media technology
media: 100baseT4, 100baseTx-FD, 100baseTx-HD, 10baseT-FD, 10baseT-HD,
       (to advertise both HD and FD) 100baseTx, 10baseT
# mii-tool eth0
eth0: negotiated 100baseTx-FD flow-control, link ok


# mii-diag --help
Usage: mii-diag [-aDfrRvVw] [-AF <speed+duplex>] [--watch] <interface>.

   Show the link status of the specified network interface.
   The default interface is "eth0".

   The common usage is
      mii-diag eth0
 Frequently used options are
   -A  --advertise <speed|setting>
   -F  --fixed-speed <speed>
        Speed is one of: 100baseT4, 100baseTx, 100baseTx-FD, 100baseTx-HD,
                         10baseT, 10baseT-FD, 10baseT-HD
   -s  --status     Return exit status 2 if there is no link beat.

 Less frequently used options are
   -a  --all-interfaces  Show the status all interfaces
              (Not recommended with options that change settings.)
   -D  --debug
   -g  --read-parameters        Get driver-specific parameters.
   -G  --set-parameters PARMS   Set driver-specific parameters.
       Parameters are comma separated, missing elements retain existing
value.
   -M  --msg-level LEVEL        Set the driver message bit map.
   -p  --phy ADDR               Set the PHY (MII address) to report.
   -r  --restart        Restart the link autonegotiation.
   -R  --reset          Reset the transceiver.
   -v  --verbose        Report each action taken.
   -V  --version        Emit version information.
   -w  --watch          Continuously monitor the transceiver and report
changes.

   This command returns success (zero) if the interface information can be
   read.  If the --status option is passed, a zero return means that the
   interface has link beat.
# mii-diag eth0
Basic registers of MII PHY #1:  3000 7809 02a8 0154 05e1 0000 0000 0000.
 Basic mode control register 0x3000: Auto-negotiation enabled.
 Basic mode status register 0x7809 ... 7809.
   Link status: not established.
   End of basic transceiver information.

-- 
Martin A. Brown --- SecurePipe, Inc. --- mabrown@securepipe.com

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