Slower Laptop Network Speeds
For the past few weeks I noticed network connectivity had slowed on the T400 laptop.
At one time I had been running a cron job to test connectivity within the LAN. A shell script wrapper to iperf. The logs I created showed a continual stream of hourly results and then they stopped. No surprise because I remembered stopping the cron jobs. There was a couple of manually iperf results at the end of the log. Those manual tests showed I was seeing about 95 Mb/s bandwidth with wireless.
A fresh iperf test showed the laptop running at half that speed. That the numbers were half seemed peculiar and seemed to provide a clue.
I scratched my head. What did I do to cause the slower results? I tinker a lot with the computers. I knew I had done something.
I have a good backup plan. I looked at the date of the last good iperf test in the log. I diffed (
diff -qr) the
/etc directory in the backups from just before that date against the current
Quickly I found the cause of my self-inflicted pain. I had disabled an option in
/etc/modprobe.d that enabled link aggregation. I had commented out the option while performing some testing on the laptop. I forgot to restore the option.