Far fewer "Bad TCP" frames using linux

Discussion in 'other software & services' started by wat0114, Jun 5, 2008.

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  1. wat0114

    wat0114 Guest

    This is not a thread to promote Linux, only an observation I'd like to share.

    • Using Wireshark to capture data in a simple experiment run under both Windows XP Pro and Linux (PCLinuxOS 2007), same hardware because I'm using dual boot for the OS's.
    • Browser is Firefox
    • PC is behind older D-Link router (DI-624)
    • I have also under Windows disabled TX/RX checksum offload under NIC's properties

    1. First start Wireshark to capture on my NIC's interface
    2. Open Firefox to homepage (Google.ca)
    3. Open Wilderssecurity.com
    4. Open tsn.ca
    5. Stop Wiresharkcaptuere after tsn.ca loads

    This same experiment repeated two more times, then thee times again with my software firewall and Ad muncher shut down.

    Then boot to linux and repeat same experiment as above, three consecutive times as well. Only security with Linux is iptables firewall.

    I take note of number of "Bad TCP" frames under all conditions, and Linux count of these frames is at least 75% less than that of Windows.

    I don't know the reason for this. Perhaps Linux does a better job of handling TCP/IP traffic? Anyways, I find it interesting.

    Sorry, I forgot to mention there is little difference in "total" frame count in the experiments between Windows and Linux, so there does not seem to be more overhead in windows because of more bad tcp frames. Obviously this is a good thing.
    Last edited by a moderator: Jun 5, 2008
  2. Mrkvonic

    Mrkvonic Linux Systems Expert

    May 9, 2005
    Do you have the same MTU set in both Windows and PCLinuxOS?
  3. wat0114

    wat0114 Guest

    Yes, set @ 1500 for both OS's. I've played with those settings before in Windows and found little to no difference with regards to packet captures. What is odd is that even with the RX/TX checksum offloads set to disable for my NIC under Windows, I'm still seeing so many of those "bad packets".

    As an aside, my daughter wants Linux installed on her computer. She finds her favorite Flash games run considerably faster on it :)
  4. Arup

    Arup Guest

    Not surprising as Linux kernel is far more optimized and the TCP stack is a reflection of that, IP tables also runs way better than Windows inbuilt firewall.
  5. NGRhodes

    NGRhodes Registered Member

    Jun 23, 2003
    West Yorkshire, UK
    Sorry to change the subject, which version of Flash are you using, I tried the latest Office with Ubuntu 8.04 and its performance is OK with youtube, but terrible with games, compared to windows.
  6. wat0114

    wat0114 Guest

    No troubles. I have to check later at home. I was using and liking Ubuntu until a recent spate of updates, around 60 of them I think, that caused performance issues with it. I decided to try PCLinux and find it awesome, so I'll stick with it for now. I'm impressed with the KDE environment.


    Java version: Sun for PCLos2007
    Last edited by a moderator: Jun 6, 2008
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