As a test to see if this fix will work for you, log in as root, cd to /System/Library/ and delete or move the "Extensions.mkext" file. Reboot. If your system takes about 6-8 minutes to reboot, and the NetInfo application in /Utilities/ which had never worked before will now come up and give you network information, this fix might work for you.
Read the rest of the article for the steps to take to implement this fix...
The problem is that the Extensions.mkext file that lives in /System/Library/ does not contain the necessary information to initialize the network on boot. This file is created by the rc script (/etc/rc) at this point:
if [ ! -f /System/Library/Extensions.mkext -o \If you do a man on kmextcache, you'll see that there is a "-n" option to load the system extensions that have the OSBundleRequired key set to "Network-Root". So, to force mkextcache to do this, edit the rc file in root mode and add the "-n� option. Mine looks like this:
/System/Library/Extensions.mkext -ot /System/Library/Extensions ]; then
if [ "${SafeBoot}" != "-x" ]; then
ConsoleMessage "Updating kernel extensions cache"
rm -f /System/Library/Extensions.mkext
/usr/sbin/mkextcache -l -t `arch` -o /System/Library/Extensions.mkext \
-d /System/Library/Extensions
fi
fi
/usr/sbin/mkextcache -l –n -t `arch` -oSave the rc script and again remove or rename the Extensions.mkext file in /System/Library/. Reboot.
/System/Library/Extensions.mkext \
-d /System/Library/Extensions
Your system will take about 6-8 minutes to reboot as it rebuilds the .mkext file. Check the NetInfo application in /Utilities/ to see if networking is running. If it is, reboot again. This is the real test. The system should boot much faster this time because it's using the .mkext file to load the necessary extensions instead of looking through each one to check the OSBundleRequired key. Check the NetInfo application. If it's working and you have access to your ethernet, you're problem is solved (until something overwrites the rc script, which system updates might do – I'm not sure).
Also, make sure that in NetInfo Manager under Config - AppleFileServer - use_appletalk is set to '1'.
[Editor's note: I'll admit ignorance on this one, but if you're having AppleTalk problems, this could be a worthy troubleshooting step.]

