Hacking a Netgear DG834G

[DavidP]

Hi All

I have just got iBurst and 1 big problem is only one pc can connect at a time. Now what i need is a broadband router. What I have is a Netgear ADSL router.

Question: Can the netgear be hacked into using one of the ethernet ports as the wan device ?

Anyone ?

[Ekhaatvensters]

Yes.

Someone else will hopefully explain, its not that hard though.

You just get your PC to connect to whatever IP the modem is given by the router.

[DavidP]

I have got Telnet access to the device just not too sure from there.

[Gambit]

I used these routers for a couple years and played around with them quite a bit and as far as i know you cannot reroute the wan port away from the adsl modem and on to one of the 4 ethernet switch ports. The router can only be used as an ethernet switch and a wireless access point if adsl is not used.

[DavidP]

What I found so far :

cat /usr/etc/default | grep wan
wan_ifname=nas0
wan_mode=
wan_iptype=Dynamic
wan_ipaddr=
wan_netmask=
wan_gateway=
wan_mtu=1458
wan_fix_dns=0
wan_dns1=
wan_dns2=
wan_macaddr=
wan_encap=1
wan_vpi=8
wan_vci=35
wan_account=
wan_domain=
wan_dod=1


But don't know how to edit the file vi is not loaded :

Currently defined functions:
[, ash, busybox, cat, chmod, cp, dd, dmesg, echo, egrep, false,
free, grep, ifconfig, init, insmod, kill, killall, ln, ls, lsmod,
mkdir, modprobe, more, mount, mv, ping, ps, reboot, rm, rmmod,
route, sh, sleep, test, touch, true, umount, wget

[tibby.dude]

I used these routers for a couple years and played around with them quite a bit and as far as i know you cannot reroute the wan port away from the adsl modem and on to one of the 4 ethernet switch ports. The router can only be used as an ethernet switch and a wireless access point if adsl is not used.

It is possible in theory as the embedded ethernet switch in the DG834 is a 6 port Marvell 88E6060 which is a fully programmable switch with VLAN support.

The problem is that nobody afaik has sucessfully ported OpenWRT to this router as most people are interested in the WRT54G family when it comes to hacking such stuff.

My advice is to save yourself some grief and wasted time and just spend the R500 for an el cheapo wireless router.

[Ekhaatvensters]

Ag ja, listen to tibby.

Unless you find a guide somewhere on the net (myADSl probably isnt the place unless Seburn can help) then just buy some router that will work, you can sell your current one, probably almost break clean as that one is worth more than a normal router.

[seburn]

Hey he clearly knows more than me about that router.

What port did you telnet in on as a matter of interest? Maybe I can use this to hack the Wan ip and enable a second route to the iburst modem on other netgear models.

Yeah vi would be nice though, kinda need it.

Are those the only functions?
Is sed loaded ...http://www.computerhope.com/unix/used.htm
If so I will have to search me notes to remember how to use it.

[DavidP]

Open the telnet port:
http://<RouterIP>/setup.cgi?todo=debug

Then telnet in to the IP. Tada!

Simple as pie.

[DavidP]

The problem is that nobody afaik has sucessfully ported OpenWRT to this router as most people are interested in the WRT54G family when it comes to hacking such stuff.

My advice is to save yourself some grief and wasted time and just spend the R500 for an el cheapo wireless router.

Yes had a look at OpenWRT not looking to good yet.

I have already ordered a cheep WAN router R300 for Dlink DL-604. Seems like netgear will just have to be an access point for now ;) .

[DavidP]

Replying to my own posts here but hey !


How to extract and recreate your own firmware image?

1.
retrieve an official image from netgear
ftp://downloads.netgear.com/files/dg834g_v1_04_01.zip or any newer one.
Here is the last and new one :
ftp://downloads.netgear.com/files/dg834g_3_01_25.zip


2.
extract the cramfs image from the firmware image:
$ ./dgfirmware -x cramfs_v1_04_01.img dg834_v1_04_01.img


3.
mount the cramfs image (you must be root) and save the filesystem:
$ mkdir target
$ su
$ mount -o loop cramfs_v1_04_01.img target
$ cd target
$ tar -cf ../cramfs_v1_04_01.tar .
$ cd ..
$ chown gilles:gilles cramfs_v1_04_01.tar
$ umount target
$ exit


4.
modify whatever you want in the root filesystem (see FirmwareModifications):
$ cd target
$ tar xvf ../cramfs_v1_04_01.tar (you may need to be root for this step otherwise tar may not be able to create device nodes)
$ ...
#$ echo "0.00.01" > ./usr/etc/version
$ tar cf ../cramfs_opendg_0_00_01.tar
$ cd ..


5.
create a new cramfs image:
$ fakeroot /sbin/mkfs.cramfs target cramfs_opendg_0_00_01.img


6.
merge the new cramfs image in the original firmware image:
$ dgfirmware -m cramfs_opendg_0_00_01.img -w opendg_0_00_01.img dg834_v1_04_01.img
(don't bother of the version message shown dgfirmware it does not refer to the version number in the cramfs)


7.
Upload the new firmware to the DG834 through the router web interface or through the Recovery Utility.


8.
Enjoy!

I'll see what I can do ?

[seburn]

Maybe the source might help? http://kbserver.netgear.com/inquira/default.asp?ui_mode=answer&prior_transaction_id=111904&action_code=5&highlight_info=16778096,2766,2773&turl=http%3A%2F%2Fkbserver.netgear.com%2Fkb_web_fi les%2Fn101238.asp&answer_id=4833715#__highlight