10.4.8 crashes with Jumbo frame sizes (gigabit ethernet)

Discussion in 'macOS' started by dmelgar, Dec 28, 2006.

  1. dmelgar macrumors 68000

    Joined:
    Apr 29, 2005
    #1
    Hello, I'm trying to network from my Macbook to a computer with a realtek 8169 gigabit ethernet card using a crossover cable. If I set the MTU size greater than 1500 the Mac crashes frequently.

    This seems like a very common scenario. Has anyone else experienced this?
    Are jumbo frame sizes still too new, bugs not worked out? I tried networking between the Macbook and an IBM T41. If using jumbo frame sizes the Thinkpad crashes. What gives?

    I've also noticed that if I do an NFS mount with default parms, ie using UDP, that the connection is amazingly slow, ie max 1MB/sec. If I force it to use TCP, I get 10-13MB/sec. Any ideas why thats happening?

    I'm surprised to have found a scenario which consistently crashes an otherwise very reliable system.
     
  2. ClimbingTheLog macrumors 6502a

    Joined:
    May 21, 2003
    #2
    I'm seeing the same thing - the gigabit card is a netgear, MTU set to 7200. I've tried 9000 and 7200 on the MacBook. Ka-boom. If I set it to 1500 everything works stably.

    I'm using a gigabit switch - not sure if it supports jumbo frames itself. I'd guess your cross-over cable either doesn't support it at all, or supports it implicitly. I'm not sure here, but a kernel panic is definitely the wrong behavior.
     

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