ndt-users list created

[Simon Leinen <>]

Thanks Jakub and Richard, for the new NDT version.
It looks great so far.  IPv6 support is particularily welcome!

With previous versions, it was relatively easy to get the command-line
client (web100clt) running on non-Linux systems such as Solaris.
Unfortunately this seems to have become a little more difficult.  I'll
send a patch in a separate message.

Anyway, I got the client working now, and it seems to work fine over
IPv6, against a freshly installed NDT 3.3.12 server on a Linux
2.6.17+Web100 box:

    : 
leinen@diotima[src];
 ./web100clt -n lsmp2
    Testing network path for configuration and performance problems  --  
Using IPv6 address
    Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
    checking for firewalls . . . . . . . . . . . . . . . . . . .  Done
    running 10s outbound test (client to server) . . . . .  721.32 Mb/s
    running 10s inbound test (server to client) . . . . . . 497.59 Mb/s
    The slowest link in the end-to-end path is a 2.4 Gbps OC-48 subnet
    Server 'lsmp2' is not behind a firewall. [Connection to the ephemeral 
port was successful]
    Client is probably behind a firewall. [Connection to the ephemeral port 
failed]
    Information: Network Middlebox is modifying MSS variable (changed to 
16376)
    Server IP addresses are preserved End-to-End
    Client IP addresses are preserved End-to-End

I'm sure there are no MSS-rewriting middleboxes between the two hosts,
and MSS=16376 seems a bit on the high side - the Ethernet on the
client (Sun) has 1500 byte MTUs, and the interfaces on the server have
9000 byte MTUs.  But the Linux NDT server logs

    Sending 16364 Byte packets over the network
    libweb100: warning: accessing depricated variable AckPktsIn
    libweb100: warning: accessing depricated variable AckPktsOut
    Sending 16364 Byte packets over the network

This must have been derived from the lo (Loopback) interface, which
has an MTU of 16436 bytes:

    lo        Link encap:Local Loopback  
              inet addr:127.0.0.1  Mask:255.0.0.0
              inet6 addr: ::1/128 Scope:Host
              UP LOOPBACK RUNNING  MTU:16436  Metric:1
              RX packets:21058 errors:0 dropped:0 overruns:0 frame:0
              TX packets:21058 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:0 
              RX bytes:3564404 (3.3 MiB)  TX bytes:3564404 (3.3 MiB)

And I still have an issue using the client over IPv4.

    : 
leinen@diotima[src];
 ./web100clt -4 -n lsmp2
    Testing network path for configuration and performance problems  --  
Using IPv4 address
    Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Protocol 
error!
    : 
1leinen@diotima[src];
 

I'll dig further into this.  I already checked that I can telnet to
the IPv4 address of "lsmp2".

Anyway, who uses IPv4 anymore?

Regards,
-- 
Simon.