OK ****! - was I wrong...
After the above entry I packed up my MacBook, headed out to the Mac store and dropped it for repair; they had it overnight. "The Genius" called me to pick it up the next day. The answer:
There's nothing wrong with your MacBook. They copied files back and fourth between my MacBook and many other hosts on their network; it performed as expected.
I gave him a short history of the problem, and he said, "OOOOOooohhh, it's the Belkin." I brought my baby home, did a little research, found that others had a similar problem and found an acceptable fix. I ordered the new switches, a 5-port for my desk and an 8-port for the servers in the back room; incidentally, these items were inexpensive.
I swapped out the Belkin F4G0500 for the TrendNet TEG-S50g and everything started popping:
- The MacBook received (and retained) a DHCP lease
- Files copied between the Mac and other hosts at gigabit speeds
I should say the rest of my gear, 3 Linux Servers, a Linux Desktop/Laptop, and printer all made use of the Belkin at gigabit speeds (100MB file between Host A <--> Host B in 2 seconds), it was only the Mac that had trouble with the Belkins.
I split this evenly between Belkin and Apple as a responsibility to fix for we the buyers. It's 2012, we should have layer 3 (switching) sorted out by now. This was minor but pricey pain in the ***.
Troubleshooting Techniques:
Create Files of a Specific Size
You can use the "dd" (Unix) program to create files of a specific size. To test gigabit speeds, specific file sizes take the guessing out of the equation.
- Open the Terminal (Utilities directory)
- To create test files, enter both of the following lines (line one, then line two, giving each time to finish):
- dd if=/dev/zero of=~/Desktop/output_100MB.dat bs=1M count=100 # Creates a 100MB file
- dd if=/dev/zero of=~/Desktop/output_1GB.dat bs=1M count=1000 # Creates a 1GB file
- The files created in Step 3 will now be on your desktop ready for transfer/testing.
- Quit the Terminal.
File Transfer Calculator
This calculator will give you an approximation of what transfer times should be; at least it's close enough for me. There will be a little flux due to various (network) conditions, within 2-3 seconds it seems, but generally these estimations should hold.
For my problem, I wanted to test a 100MB & 1GB file transfer between 2 computers (both with Gigabit Network Cards) on the same switch.
EG: for the 2 files, I fill in the calculator:
100MB file: Size: 100; Size Lable: MB; Speed Lable: -none ; Select Speed by interface: Wired Lan Gigabit Ethernet --> click Calculate = estimated 2 seconds.
1GB file: Size: 1; Size Lable: GB; Speed Lable: -none ; Select Speed by interface: Wired Lan Gigabit Ethernet --> click Calculate = estimated 9 seconds.
Verify Gigabit Speeds on the Switch
The Trendnet ports will light up GREEN for each port that is functioning at gigabit (1000 Mbit/s) speeds; ports that are only running at Fast Ethernet speeds (100 Mbit/s) will light up AMBER. Transfers must occur between any 2 computers lit green on the switch.
When I copy the files to another (host) computer I see transfer times for:
- The 100MB file is on the money: 100MB 50.0MB/s 00:02 seconds.
- The 1GB file takes a little longer: 1000MB 47.6MB/s 00:21
Here we see approximately 50.0MB/s transfer times for both. The File Transfer Calc estimate was off by 12 seconds but I did notice that the transfer degraded slightly (in speed) the longer it persisted; even though that's true, the MB/s is similar.
If you have a similar setup as me (1 switch under your desk, and 1 in the server room), repeat the transfers to (hosts) computers in the back room with a green light on the switch. The transfers should be similar if not the same.
It's not perfect but it's a week later and I'm almost $200 down; it's close enough for jazz and better than what I had before. I'm tired of screwing with it.
Cheers all,
TT