I haven't used any RH software since the before they split RHEL/Fedora so I am a little out of date on this. But I did wonder whether you want PEERDNS=yes. I also have no idea what the SEARCH= line does.
The first thing I suggest is looking through whatever log file shows boot messages and see if you spot any errors related to this. Another, admittedly somewhat desperate move, would be to (temporarily) modify the ifup
script (assuming it is still a script rather than a binary, and assuming that script is where the interface is actually brought up) such that it logs everything it is doing, and then after boot examine the log to see if you can figure out what is going on. If you do this make sure
to backup the original version of the script before modifying. If ifup
is a bash script you can accomplish what I suggested by adding the following two lines toward the top of the script.
exec 2> /tmp/ifup.log
Of course, you can change the file name /tmp/ifup.log to anything you want.