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Return to USB Networking.

Personal tools

Neo1973 side

Name resolution

By default Neo1973 has usb0 interface working due to Ethernet gadget (g_ether) compiled into kernel.

On the Neo, if you want to reach out to the internets using full qualified hostnames, you need to define your DNS server. Create a file /etc/resolv.conf with at least one line saying


e.g. nameserver

Then you can also easily update your 2007.2 OpenMoko packages with "ipkg update && ipkg upgrade" on the Neo.

A better approach is to symlink

ln -s /var/run/resolv.conf /etc/resolv.conf

and fill the file at bootup with a script /etc/network/if-up.d/08setupdns containing:

#!/bin/sh -e
echo  nameserver > /var/run/resolv.conf

this way the file is correctly handled from ppp package when dialing into gprs.


You need a additional route for traffic to the internet. This traffic can be routed through your pc (see below) if the pc is the default route destination. you can achieve this by adding


to your /etc/network/interfaces in the usb0 section.

Desktop side

Manual method

With the device connected, modprobe usbnet module and configure usb0 interface (as root):

ifconfig usb0 netmask

If your eth0 interface is also in the same 'range' (e.g. then you can do the following:

1. ping the Neo with

# ping -I usb0

2. add a route to your Neo:

# /sbin/route add -host dev usb0

3 log in to the Neo

# ssh root@

If you don't have the necessary modules to get usb0 going, make sure you have the following kernel options enabled:


Both options are available in the Device Drivers -> USB support -> USB Network Adapters. For more info see the usbnet driver homepage.

Automatic method

Took from Hotplugging usbnet post by Marcin 'Hrw' Juszkiewicz.

Debian or similar

Edit /etc/network/interfaces:

allow-hotplug usb0
iface usb0 inet static
        post-up iptables -A POSTROUTING -t nat -j MASQUERADE -s
        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up iptables -P FORWARD ACCEPT

Ubuntu (Tested with Feisty and Gutsy)

Edit /etc/network/interfaces:

auto usb0
iface usb0 inet static
        up iptables -A POSTROUTING -t nat -j MASQUERADE -s &
        up echo 1 > /proc/sys/net/ipv4/ip_forward &
        up iptables -P FORWARD ACCEPT &
        down iptables -D POSTROUTING -t nat -j MASQUERADE -s &

If you are doing the echo 1 > /proc/... command manually, sudo may not be enough, then you will have to execute it from a sudo bash.

Ubuntu Feisty and Gutsy appear to have a bug where ifdown is not run when the interface is unplugged, meaning this only works once after the system is booted. One can patch /etc/udev/rules.d/85-ifupdown.rules, editing the two lines at the end of the file:

SUBSYSTEM=="net", DRIVERS=="?*", GOTO="net_start"


# Bring devices up and down only if they're marked auto.
# Use start-stop-daemon so we don't wait on dhcp
ACTION=="add",          RUN+="/sbin/start-stop-daemon --start --background --pidfile /var/run/network/bogus --startas /sbin/ifup -- --allow auto $env{INTERFACE}"


ACTION=="remove",       RUN+="/sbin/start-stop-daemon --start --background --pidfile /var/run/network/bogus --startas /sbin/ifdown -- --allow auto $env{INTERFACE}"

the bug is that the LABEL="net_end" is at the wrong position



# USB configuration for PDAs (openmoko)

Fedora (Tested with FC8)


# USB configuration for PDAs (openmoko)
# from

Red Hat or similar

Edit /etc/sysconfig/network-scripts/net.hotplug:

After this command

    case $INTERFACE in
	# interfaces that are registered after being "up" (?)


		ifconfig usb0 netmask
		route add usb0
		iptables -I INPUT 1 -s -j ACCEPT
		iptables -I OUTPUT 1 -s -j ACCEPT
                iptables -A POSTROUTING -t nat -j MASQUERADE -s
                echo 1 > /proc/sys/net/ipv4/ip_forward
		exit 0


  • Open /etc/conf.d/net and add:
# Neo1973
config_usb0=( " netmask" )
routes_usb0=( " via" )
  • Create a new init script:
cd /etc/init.d
ln -s net.lo net.usb0
  • Put iptables into use:
iptables -I INPUT 1 -s -j ACCEPT
iptables -I OUTPUT 1 -s -j ACCEPT
iptables -A POSTROUTING -t nat -j MASQUERADE -s
  • Store them
/etc/init.d/iptables save
  • If you want the routing by default:
rc-update add iptables default


Install AJZaurusUSB, open System Preferences / Networks and configure the interface for Manual DHCP with Host address and Gateway

Mobile development

Proxying DNS requests

If, like me, you move about quite a lot, connecting to various networks as you go and getting your ip via dhcp, you'll probably be annoyed at having to constantly update your resolv.conf on the Neo 1973.

To get round this, as part of my setup script, I run a proxy dns on the ip address the neo comes in on at the usb0 port. This means that my Neo /etc/resolv.conf only contains:


and my laptop will proxy all dns requests based on it's own /etc/resolv.conf

note that we only run the dns proxy on the usb0 interface so that we don't break any other networking

Proxying with dnrd

The script is designed to use dnrd as the dns proxy. The script and a copy of dnrd are available from my site. The script also performs the initial setup of the connection as per the USB_Networking#Manual_method above.

Proxying with a UDP forwarder

Another easy setup is using a udp forwarder like the one from - is use it with the command

       -f=`cat /etc/resolv.conf|awk '$1 == "nameserver"{print $2; exit(0);}'`:53

Proxying with iptables

Its is possible to forward DNS requests with iptables using the DNAT target

iptables -t nat -A PREROUTING -p tcp -s -d --dport domain -j DNAT --to-destination
iptables -t nat -A PREROUTING -p udp -s -d --dport domain -j DNAT --to-destination

where is the IP of your residential gateway (router). This is the easiest method, but its not recommended if you have a direct connection to the Internet as ISP DNS servers can change, and this does no load-balancing.

Connecting to phone

Then ssh root@ with empty password to get into phone.

NOTE: the ssh daemon (dropbear 0.49) on the OpenMoko appears to have a bug when sending the exit status back to the client. From time to time you receive an exit status of 255.

SSH Extras

If you get fed up with typing root@, on your PC edit /etc/hosts and add an entry for 'phone' phone

then edit ~/.ssh/config (or create it) and add

host phone
user root

then all you need to do is type

# ssh phone

To avoid ssh added a new line for every ssh host-key to you known_hosts you can add the following to the phone section in ~/.ssh/config

 UserKnownHostsFile /dev/null

You might want to use keys to bypass the login prompt too.

SSH Keys

From host to phone

To generate ssh keys for use as a login mechanism type

ssh-keygen -t rsa

when prompted for a password either hit enter for no password (not really a good idea) or enter a password for this key. ssh into the phone and create ~/.ssh

# mkdir ~/.ssh

then from your PC copy the .pub file to the phone.

# scp ~/.ssh/ phone:.ssh/authorized_keys

You should now be able to ssh directly into the phone.

To disable password logins (after setting up key access) edit /etc/init.d/dropbear and change the following line:




You will need to restart dropbear for this to take effect.

From phone to host

Generate the key

 dropbearkey -t rsa -f id_rsa

The output will look something like this:

 Will output 1024 bit rsa secret key to 'id_rsa'
 Generating key, this may take a while...
 Public key portion is:
 ssh-rsa AAAAB3Nza[...]
 Fingerprint: md5 ca:e8:f0:b7:f6:7b:c2:b6:b9:71:e4:45:86:a9:ff:b8

Copy and paste the one line (in this example, starting with 'ssh-rsa' onto the end of the host's authorized_keys file (often in ~/.ssh/).

From the phone, ssh with -i:

 ssh -i id_rsa user@host

This works for me. I ripped off these instructions from: [[1]]

GUI on desktop through SSH

If you need to get the GUI on the phone onto the desktop via usb, you can use ssh as follows

 ssh -l root -X -v

Login, and run openmoko-finger-demo for example, and it will open up on the desktop. To get landscape view, just resize the GUI window on the desktop.

Remote apps on neo

To get desktop apps to show up on your neo, first log in to the phone

 ssh -l root

Then once inside, run:

 DISPLAY=:0 xhost +

After this you can close the ssh session. Back on the desktop computer, run:

 DISPLAY=moko:0 xclock

Note that the xhost command will allow remote applications on to access the X server. It will allow anyone on the desktop machine to access the X server of the neo, including snooping anything you type on it. To disallow remote applications again, run this in the neo:

 DISPLAY=:0 xhost -