Re: UDP packet handling weird behaviour of various operating systems

From: Stefan Laudat (stefanat_private)
Date: Wed Jul 25 2001 - 15:59:59 PDT

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    > Most UDP packets should be firewalled from the Internet.
    
    Agree.
    
    > This is only really useful if someone has access to the local network. Is
    > Linux/UP actually *locking* or just temporarily unresponsive? Also, it is
    > invalid to compare Windows ME running on $3000 hardware with Linux/*BSD
    > running on an old Pentium. Are you running all of this on the same
    > hardware? Obviously faster hardware is going to be affected less by a UDP
    > flood. How about the network cards?
    
    Identical network cards for Win2k, Linux SMP and OpemBSD processor (Intel
    Pro 100). Linux was run on dual p3/1Ghz(SMP), Pentium2/400Mhz and P3/800Mhz
    (UP). Windows 2000 was run on p3/1Ghz UP. I've made tests with same results
    against Linux UP boxes running on Celeron/600 with 3com Vortex and realtek
    8139 NICs. I've outlined that the result is the same no matter if you hit
    via 1Gbit or 100Mbit. 
    
    > I am suspicious that you are just comparing hardware, given that different
    > versions of W2K perform much differently in your analysis. (You said the
    > load was server: 35%, professional: 60%) I somehow doubt that MS tuned the
    > network stack so much on the ``server'' version & wouldn't do the same on
    > the ``professional'' version.
    
    Some of the Linux servers have just the same configuration with the w2k
    servers. The reaction IS different. That's what amazes me. Also WinME was
    run on a cheap p2/350 box with an old intel NIC. No slowdown at all :(
    
    > I bet a Sun E10K with lots of NICs could flood the Sun UE3500 with lots of
    > NICs, but that probably doesn't mean that the Solaris 8 network stack is
    > better than the Solaris 8 network stack; it's because the E10K is faster.
    
    well then someone will clear all this stuff for me.
    
    -- 
    Stefan Laudat
    CCNA,CCAI
    Senior Network Engineer
    Allianz-Tiriac SA
    
    "Let's call it an accidental feature."
            -- Larry Wall
    



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