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+Fixing Android MAC Address Conflicts
+====================================
+
+If you already know this is the fix for your issue, you can skip this section.
+Otherwise, I'll get on to describing the problem.
+
+I have been frustrated for the last few days with my phone. I have run
+CyanogenMod for a while now on my LG G3 (since the early alpha builds), while
+my wife ran a variant of the stock carrier rom. However, due to poor battery
+life issues, she wanted to have CyanogenMod since my phone gets about twice as
+much battery life than hers does. Obligingly, I flashed CyanogenMod on her
+phone. That night I noticed a problem was occuring with both of our phones,
+which I unfortunately didn't realize the source of until today.
+
+[[symptoms]]
+Symptoms
+~~~~~~~~
+
+The symptoms of the issue were wifi was repeatedly dropping. Rebooting wifi
+and/or toggling airplane mode would fix the issue for a few minutes, but it got
+progressively worse. A few hours before writing this post, it was so bad I
+could only maintain a wifi connection for about 10 seconds before it would fail
+and not even try to reconnect for about five minutes.
+
+[[the-problem]]
+The Problem
+~~~~~~~~~~~
+
+After puzzling through the issue, it occured to me what it must have
+been: conflicting mac addresses.
+
+I checked my wife's and my phones and sure enough, their mac addresses were
+identical, specifically **00:90:4c:c5:12:38**. I did some Googling and found
+many other people to have the same issue in varying versions and roms of
+Android. After some hunting, I found a
+http://forum.cyanogenmod.org/topic/105128-wifi-bug-cm12/[temporary fix], but
+the fix was for a different phone, which stored its config files in a different
+location (oddly). I did a bit of digging through the filesystem (+find /system
+-type f -exec grep -H macaddr "\{}" \;+) and finally found the file that needed
+to be modified for my phone/version of Android. For reusability purposes, I
+also turned this into a _fairly_ friendly script so other folks can do it too.
+
+Note though that this issue is very obscure and the likelyhood of seeing is it
+slim. Only people running at least two phones with this bug at the same time
+and on the same wifi network will experience this issue. This is why my phone
+operated fine for months until I put CyanogenMod on my wife's phone and she
+connected to our wifi. Further (to the credit of the CM and the various other
+Android devs out there), this problem would be tremendously difficult for a dev
+to track down because it is only problematic with two or more phones, something
+I doubt most devs are testing at the same time with.
+
+[[the-fix-script]]
+The Fix Script
+~~~~~~~~~~~~~~
+
+This script needs to be run as root to work correctly (if you don't run it as
+root, it'll complain at you and exit). Once you've run this script as root,
+simply reboot your phone and your new mac address will take effect.
+
+----
+#!/system/xbin/bash
+
+# Ensure we are running as root, because this won't work otherwise.
+uid=$(id | sed -n 's/uid=\([0-9]\+\).*/\1/p')
+if [[ ${uid} != 0 ]]; then
+  echo "Not running as root. Cannot proceed. Exiting..."
+  exit 1
+fi
+
+echo "Remounting /system with write access so we can make the modification."
+mount -o remount,rw /system
+
+# The path to the wlan cal file
+cal_path=/system/etc/wifi/bcmdhd.cal
+
+# Don't need this, but might be handy to have documented
+#old_mac=00:90:4c:c5:12:38
+
+# Generate the new mac address
+new_mac=$(printf '00:90:4c:%02x:%02x:%02x\n' $[RANDOM%256] $[RANDOM%256] $[RANDOM%256])
+
+# Sed expression to replace the mac address with something less problematic
+sed -i "s/macaddr=.*/macaddr=${new_mac}/" ${cal_path}
+
+echo "Your new mac address is ${new_mac}."
+----
+
+I personally placed this on my internal storage at /storage/sdcard0/mac_fix.sh.
+To execute it, as root just run...
+
+----
+bash /storage/sdcard0/mac_fix.sh
+----
+
+Note the preceeding call to the bash command. Ordinarily you would be able to
+set the execute bit on the script and directly call it. However, Android
+defaults to setting the noexec mount option for the sdcard filesystems (both
+sdcard0 and sdcard1), thus chmod +x doesn't work. This could be worked around
+in the script, but it would make it longer and I don't see the need for it. :)
+
+
+// vim: set syntax=asciidoc: