MID7035-4 Changing MAC Address on Each Restart

FrankS

Member
Jan 1, 2014
5
0
I just purchsed this tablet as a refurb from Newegg, and generally I've very pleased with it. My sole issue with it is this: THe MAC address changes everytime it is powered off and back on again.

First off, other than deliberate hacks and spoofs, I didn't think this was possible. It's a serious problem for me since my wireless AP uses MAC filtering as a part of my network security. Therefore, I have to go into the router to change the tablet's MAC in the 'allow' table to get it to connect.

I have tried various searches to find information, but the only things I found were dead ends.

Anyone have any ideas?
 

FrankS

Member
Jan 1, 2014
5
0
Ok never heard of this, does the tablet factory reset each boot or just lose wifi?

The best I can tell, only the MAC address changes. It's definitely not a factory reset as everything like the wallpaper, sound settings, DL'd apps remain unchanged.
Also, to be clear, the WiFI remains working, but since the MAC has changed, my AP simply refects the connection.
 

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
The best I can tell, only the MAC address changes. It's definitely not a factory reset as everything like the wallpaper, sound settings, DL'd apps remain unchanged.
Also, to be clear, the WiFI remains working, but since the MAC has changed, my AP simply refects the connection.

I can't think of anyway that the MAC address would change unless you are using the wrong MAC address, Where are you getting the tablet's MAC address from?
 
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FrankS

Member
Jan 1, 2014
5
0
I can't think of anyway that the MAC address would change unless you are using the wrong MAC address, Where are you getting the tablet's MAC address from?

Settings>About Tablet>Advanced ..going off the top of my head here since I dn't have the tablet in front of me at the moment. I have noticed that the MAAC addy from this location, and the one found under Wireless>Advanced are not always the same. However, the Settings>About>Advanced route is the one the AP always sees.

And you make my point exactly. To my knowledge, this really shouldn't be possible.
 

vampirefo.

Senior Member
Developer
Nov 8, 2011
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Ok makes a little more sense to me, you are relying on the tablet's software to tell you the MAC address.

Lets find how many MAC address your tablet has, and then let's find the one related to wifi.


adb shell

Code:
busybox ifconfig -a | busybox awk '/HWaddr/ {print "Interface: " $1 "\t MAC: " $NF}'

my output from tablet I am using right now.

Interface: gre0 MAC: 00-00-00-00-1F-00-40-4B-00-00-00-00-00-00-00-00
Interface: ip6tnl0 MAC: 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
Interface: tunl0 MAC: 00-00-00-00-00-00-10-00-00-00-00-00-00-00-00-00
Interface: wlan0 MAC: 20:59:A0:3D:08:9F


Ok now we see the wifi one, it's wlan0, let's target it only.

Code:
busybox ifconfig -a | busybox grep wlan0

my output from my tablet.

wlan0 Link encap:Ethernet HWaddr 20:59:A0:3D:08:9F
 

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
Off topic would you be willing to post out of

adb shell

cat /proc/mtd

and right after boot up

adb shell

dmesg > /sdcard/dmseg.txt

then upload the dmseg.txt from your sdcard.

if you would do a full dump of your tablet and upload it that would benefit a lot of people including yourself.

right now if your tablet bootloops or fails to work there is no software available to fix it.

Most people that come here with a 7035 or 7033 has already broken their tablet, and didn't backup their tablet so we can't help them fix it.
 

mcclain_ts

Senior Member
Aug 29, 2013
120
42
"Most people that come here with a 7035 or 7033 has already broken their tablet, and didn't backup their tablet so we can't help them fix it."

----------------------------------------------------------------------------------------
SO TRUE!!! Most people do act hastily (out of excitement) when they get a tablet. It DOES pay to slow down just a little, AT LEAST make a WORKING/USABLE/GOOD dump of the unit IN WORKING order, because you can SURELY save yourself a BUTTLOAD of stress and anxiety later. It WILL make recovery(should you or someone else brick/softbrick the tablet) a WHOLE LOT EASIER!!!(warm smilz) Do us all a great favor.(including yourself) Take a little time, and make those backups! Maybe not right this moment, but before the thing becomes bricked. Believe it or not, a tablet can even brick itself mysteriously. Through the download/install of some certain apps even. It is possible. So save the headaches, and get yourself a dump, or a clockworkmod nandroid backup.(If you can/possible)
Have a great day!
 

mcclain_ts

Senior Member
Aug 29, 2013
120
42
Off topic would you be willing to post out of

adb shell

cat /proc/mtd

and right after boot up

adb shell

dmesg > /sdcard/dmseg.txt

then upload the dmseg.txt from your sdcard.

if you would do a full dump of your tablet and upload it that would benefit a lot of people including yourself.

right now if your tablet bootloops or fails to work there is no software available to fix it.

Most people that come here with a 7035 or 7033 has already broken their tablet, and didn't backup their tablet so we can't help them fix it.
------------------------------------------------------7033--------------------------------------
Per Vampirefo.'s request, here's my "semi-rooted" mid7033 (USB debugging drops with each re-boot) cat /proc/mtd -

cat /proc/mtd
dev: size erasesize name
mtd0: 00a00000 00100000 "SysInfo"
mtd1: 00c00000 00100000 "Uboot"
mtd2: 02000000 00100000 "kernel"
mtd3: 01600000 00100000 "RKer"
mtd4: 18200000 00100000 "System"
mtd5: 68100000 00100000 "Data"
mtd6: 20000000 00100000 "Cache"
mtd7: 5b000000 00100000 "user"
----------------------------------------------
and my lengthy "dmesg > /sdcard/dmseg.txt" can be found on my GoogleDrive here: 7033 dmesg

Hope this helps! I still need to get this fully changed over using Vampire's methods for full root access, and so the USB debugging isn't lost on each shutdown/reboot.(I just haven't had time to use the tablet lately.) Now I see, I need to also pay attention to my previous post here too.(smilz) But I already took the time to dump this beast in advance. And the 7033s/7035s,... they are small, but a HUGE pain in the butt so far for Vampire! Thanks for ALL the time and energy you have and continue to contribute to these notorious-but-nice tablets!(warm smilz)
 
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FrankS

Member
Jan 1, 2014
5
0
I'd be happy to do that and post the results, but i need one thing first. Someone please tell me exactly HOW to get that dump. I'm decent with networking, better with PC's, but frankly I'm just startign to learn about tablets...soo..educate me, please ....
 

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
I'd be happy to do that and post the results, but i need one thing first. Someone please tell me exactly HOW to get that dump. I'm decent with networking, better with PC's, but frankly I'm just startign to learn about tablets...soo..educate me, please ....

Here is a rooting guide for 7033, don't flash the recovery or boot.img this is for 7033, the root and backup should be the same though.

http://www.androidtablets.net/forum...oby-7033-root-recovery-unsecure-boot-img.html

adb push data /data/local/tmp/

adb shell

chmod 0777 /data/local/tmp/pwn

chmod 0777 /data/local/tmp/root.sh

/data/local/tmp/pwn

exit

adb shell

/data/local/tmp/root.sh

at this point you should be rooted, your adb shell should have went from $ to #,

You should now dump your tablet.

mkdir /sdcard/dump


cat /dev/mtd/mtd2 > /sdcard/dump/boot.img
cat /dev/mtd/mtd3 > /sdcard/dump/recovery.img
cat /dev/mtd/mtd1 > /sdcard/dump/bootloader.img

busybox tar -czvf /sdcard/dump/coby_7035_system.tgz /system
 
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FrankS

Member
Jan 1, 2014
5
0
It might be a couple days, mainly because I want to carefully read through the rooting guide and have some undisturbed time to do this. But I will get it done, and upload the dump.

If I understand this right, essentially I'm producing an image of the OS as installed, but not altering any of the settings ..since I'm not doing the flash part?
 

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
It might be a couple days, mainly because I want to carefully read through the rooting guide and have some undisturbed time to do this. But I will get it done, and upload the dump.

If I understand this right, essentially I'm producing an image of the OS as installed, but not altering any of the settings ..since I'm not doing the flash part?

No problem take your time, and yes you are just copying your tablets software, not installing.
 
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