ndt-users list created

[Richard Carlson <>]

Hi Sumanth;

The NDT server and client communicate with each other over TCP port 
3001.  This allows the server to control the clients actions, 
specifying which tests to run, what test is currently scheduled, and 
the status of the completed test.  If a fault occurs, then the server 
and client can loose contact and the client will report a "Protocol error".

Since all the tests are failing, I would do the following:

1) Check to see that the web100-enhanced kernel is running.  The 2 checks are:
        a) does the /proc/web100 directory exist?  (ls /proc/web100)
        b) did the kernel mods get installed (dmesg | grep -i web100)

If either or both of these fail, then you need to rebuild/install the 
kernel.  Follow the instructions in the Install.web100 file to enable 
the options and build/install the enhanced kernel.  After a reboot, 
verify that the /proc/web100 dir exists.

2) If the /proc/web100 directory exists, then it could be a bug in 
the Web100library routines that the NDT server tripps over.  The NDT 
server supports both IPv4 and IPv6 addresses, using a set of 
functions found in the I2Util package.  By default the server uses 
IPv4-mapped addresses, and there is a bug in the web100 library when 
handling these addresses.  A simple work-around to this bug is to 
start the NDT server process with the '-4' option 
(/usr/local/sbin/web100srv -4 {other options}).  This will force the 
NDT server to use real IPv4 addresses and everything works 
properly.  There is also a patch to the lib/web100.c file that you 
can find by searching the ndt-users archive.  Installing this patch 
will correct this problem.

Check these 2 things and hopefully this will solve your problem.

Rich
At 04:36 PM 10/16/2007, 

 wrote:
> Hello All,
>
> I was able to set up ndt server and client on 2 different linux boxes.
> Server is having the Suse 10.2 linux OS and the client is on Fedora7 
> OS. When I execute the client I see the following message
>
>
> Testing network path for configuration and performance 
> problems  --  Using IPv4 address
> Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Protocol error!
> Middlebox test FAILED!
> checking for firewalls . . . . . . . . . . . . . . . . . . .  Protocol error!
> Simple firewall test FAILED!
> Protocol error!
> C2S throughput test FAILED!
> Protocol error!
> S2C throughput test FAILED!
> Protocol error!
>
> I could not figure out what these errors mean.
> What is a middlebox? I could find any information regarding this on 
> the ndt webpage too.
> Could this occur due to firewall restrictions ?
>
> Kindly can you provide me with more information regarding this.
>
> Thanks
> Sumanth

------------------------------------



Richard A. Carlson                              e-mail: 

Network Engineer                                phone:  (734) 352-7043
Internet2                                       fax:    (734) 913-4255
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