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nikita21 / ndt

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MSS modified by middlebox message displayed in statistics window even the MSS is not modified by middlebox #8

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
What steps will reproduce the problem?

1. Connect server and client in a 1GBit Switch
2. Start both servers (fakewww and web100)
3. Set the following tcp paramters in both server and client.
    echo 1 > /proc/sys/net/ipv4/tcp_moderate_rcvbuf
    echo 4194304 > /proc/sys/net/core/wmem_max
    echo 4194304 > /proc/sys/net/core/rmem_max
    echo "4096 87380 4194304" > /proc/sys/net/ipv4/tcp_rmem
    echo "4096 16384 4194304" > /proc/sys/net/ipv4/tcp_wmem
    echo "1" > /proc/sys/net/ipv4/tcp_timestamps
    echo "1" > /proc/sys/net/ipv4/tcp_window_scaling
    echo "1" > /proc/sys/net/ipv4/tcp_sack
    echo "0" > /proc/sys/net/ipv4/tcp_ecn
4. Click the start button to start the test and wait till client complete
the test.
5. Check the statistics window.

What is the expected output? What do you see instead?

It is observed that in statistics window "Information: Network Middlebox is
modifying MSS variable" message displayed. In this setup the MSS is not
modified by middlebox (switch) but the report says MSS is modified by the
middlebox. MSS value is 1488 in this case. Since the TCP option timestamps,
window scaling are enabled MSS is 1488.
If the TCP options timestamps and window scaling are disabled the MSS value
is displayed as 1460 and the messaged "Network Middlebox is modifying MSS
variable" is not displayed.

Please provide any additional information below.

Original issue reported on code.google.com by sekharn...@gmail.com on 27 Feb 2010 at 1:27

Attachments:

GoogleCodeExporter commented 9 years ago

Original comment by sekharn...@gmail.com on 27 Feb 2010 at 1:41

GoogleCodeExporter commented 9 years ago 
Removing the 'Priority' tag and replacing with a 'Severity' tag.  Un-assigning 
QA team as owner of the bug.

Original comment by jwzuraw...@gmail.com on 1 Mar 2010 at 12:27

GoogleCodeExporter commented 9 years ago

Original comment by jwzuraw...@gmail.com on 10 Mar 2010 at 8:59

GoogleCodeExporter commented 9 years ago 
Re-verified with V3.6.3 and this bug is not yet fixed.

Original comment by sekharn...@gmail.com on 10 Jun 2010 at 5:32