A standard setup for our WRT54GL machines: step to step configuration of OpenWrt's Kamikaze firmware to meet our needs for wireless clients (connecting to the internet via the wireless interface), instead of the default wireless stations (internet access point) settings
Connect the WRT machine to your computer. The default WRT firmware runs a DHCP server: on your computer run a dhcp request as following
root@yourcomputer:# dhclient
You'll have a response similar to this
(...) DHCPOFFER from 192.168.1.1 DHCPREQUEST on eth0 to 255.255.255.255 port 67 DHCPACK from 192.168.1.1 bound to 192.168.1.101 -- renewal in 86400 seconds.
So, that means that now your computer is 192.168.1.101 and the WRT machine is 192.168.1.1
With you favourite browser, go to the WRT's web page at http://192.168.1.1
You will be asked for a username ad a password: type "admin" as username and again "admin" as password.
Now that you are in the WRT's configuration page, go to "system - > administration - > firmware upgrade", and upload there the "openwrt-wrt54g-2.4-squashfs.bin" file you previously downloaded!
connect via telnet to your newly installed WRT machine:
root@yourcomputer:/# telnet 192.168.1.1
You are now logged in the WRT, you will see something like that:
Trying 192.168.1.1...
Connected to 192.168.1.1.
Escape character is '^]'.
=== IMPORTANT ============================
Use 'passwd' to set your login password
this will disable telnet and enable SSH
------------------------------------------
BusyBox v1.00 (2006.03.27-00:00+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.
_______ ________ __
| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
WHITE RUSSIAN (RC5) -------------------------------
* 2 oz Vodka Mix the Vodka and Kahlua together
* 1 oz Kahlua over ice, then float the cream or
* 1/2oz cream milk on the top.
---------------------------------------------------
root@OpenWrt:/#
Change the password to one of your choice:
root@OpenWrt:/# passwd Changing password for root Enter the new password (minimum of 5 characters) Please use a combination of upper and lower case letters and numbers. Enter new password: Re-enter new password: Password changed. root@OpenWrt:/#
Now exit the telnet client and log in again, this time with ssh
root@OpenWrt:/# exit Connection closed by foreign host. root@yourcomputer:# ssh root@192.168.1.1
You will be warned about the autenticity of "host 192.168.1.1": type "yes", and after it you will be asked to type your newly changed password for the WRT machine:
The authenticity of host '192.168.1.1 (192.168.1.1)' can't be established. RSA key fingerprint is xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx. Are you sure you want to continue connecting (yes/no)? y Please type 'yes' or 'no': yes Warning: Permanently added '192.168.1.1' (RSA) to the list of known hosts. root@192.168.1.1's password:
NOTE: if you receive a warning "(...) Host key verification failed", just delete the offending key, or, more simply and roughly, remove the following file: " ~/.ssh/known_hosts "!!!
Now that you are logged in, remove the command that loads telnet by default (we need to do so, because telnet do not asks any password or username, and we do not want anybody to access our WRT and lan !!!)
BusyBox v1.00 (2006.03.27-00:00+0000) Built-in shell (ash)
Enter 'help' for a list of built-in commands.
_______ ________ __
| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
WHITE RUSSIAN (RC5) -------------------------------
* 2 oz Vodka Mix the Vodka and Kahlua together
* 1 oz Kahlua over ice, then float the cream or
* 1/2oz cream milk on the top.
---------------------------------------------------
root@OpenWrt:~#
root@OpenWrt:~# cd /etc/init.d
root@OpenWrt:/etc/init.d# ls
S05nvram S40network S50dnsmasq S50httpd S60cron rcS
S10boot S45firewall S50dropbear S50telnet S99done
root@OpenWrt:/etc/init.d# rm S50telnet
root@OpenWrt:/etc/init.d# cd /
The NVRAM variables are global settings that our WRT will load at boot time: here we will change some default variables in order to split the wireless interface from the ethetnet (wired) interfaces. In a default openwrt firmware, the wireless and the ethernet interfaces are bridged toghether (br0), while the DSL interface is configured to be the WAN port, the gate to the Internet. By splitting the br0 bridge, we are able to use the wireless interface (eth1) as the gate to the internet: we simply set eth1 to be the WAN interface.
NOTE: we will be always able to read the NVRAM variables typing " nvram show ". Please be careul not to make any mistake by typing NVRAM variables... results could be very nasty!. Please refer to the openwrt wiki for further informations about the NVRAM (deleting invalid arguments, ...). Also remember that any changes made to the NVRAM will vanish if we do ot run " nvram commit " before rebooting the machine!!!
First of all: enable boot_wait. Waiting some more seconds to boot will be very useful to us in case we have to re-install or upgrade our machine!
root@OpenWrt:/# nvram set boot_wait=on
Now let's set the WRT to be a wireless client instead of an access point (station), as the default setting does.
root@OpenWrt:/# nvram set wl0_mode=sta
Let's split the wireless/wired bridge: we quit eth1 (wireless) from the lan devices (br0), and we set it to be used as the WAN device:
root@OpenWrt:/# nvram set lan_ifnames='vlan0 eth2 eth3' root@OpenWrt:/# nvram set wan_ifname=eth1
Automatic connection on boot:
use only if you know which channel to connect by default !!!
We can set our WRT machine to automatically access a pre-defined wireless network: before doing this, we assume that we know the following informations about the network we want to join:
In our case, we want our WRT to connect automatically to a standard connection: SSID Wireless, channel 1, not using DHCP but connecting manually to the access point located at 192.168.1.1 (though we could use wl0_proto=DHCP and omit IP, NETMASK and GATEWAY SETTINGS). That's how we set the NVRAM to connect directly on system boot to this network:
root@OpenWrt:/# nvram set wl0_ssid='Wireless' root@OpenWrt:/# nvram set wl0_channel=1 root@OpenWrt:/# nvram set wan_gateway=192.168.1.1 root@OpenWrt:/# nvram set wan_proto=static root@OpenWrt:/# nvram set wan_netmask=255.255.255.0 root@OpenWrt:/# nvram set wan_ipaddr=192.168.1.99 root@OpenWrt:/# nvram set lan_ipaddr=192.168.50.1
As you can see, we assign our WRT the IP 192.168.1.99 for the Wireless network we connect to, while we assign the IP 192.168.50.1 for the LAN network, that means this will be the GATEWAY for all the machines connecting to uor WRT's ethernet ports!
Sometimes the WRT fails to set the ROUTE rules on boot up. We can assign a static route setting a NVRAM variable, or through an init script. In this case we prefer writing an init script with the routing rule that our WRT will follow to supply internet access for the lan
root@OpenWrt:/# echo "route add default gw 192.168.1.1 eth1" > /etc/init.d/S98route root@OpenWrt:/# chmod 755 /etc/init.d/S98route
Every time we change some NVRAM variables, we have to store it into the flash memory of the WRT, otherwise they will be deleted by the next reboot. So we run "nvram commit" once every session where we changed something in the NVRAM settings!
root@OpenWrt:/# nvram commit
As a last configuration step, we add an alias to our /etc/profile, that we will use later (we still haven't installed the requesting package), but that will spare us a lot of tipping while we are looking for an Access Point to connect to! We will only have to tip "scan", instead of "wl scan ; sleep 1 ; wl scanresults".
root@OpenWrt:/# rm /etc/profile root@OpenWrt:/# cp /rom/etc/profile /etc/ root@OpenWrt:/# echo "alias scan=\"wl scan ; sleep 1 ; wl scanresults\"" >> /etc/profile
Ok, done with the configuration, the last step is to install some very useful utilities for our WRT. This is a little tricky, because we will need to connect our WRT to a working internet connection: that means that we will go to some friend with a working connection, connect our WRT to the local network, download the packages (OpenWRT uses the IPKG system, that is very similar to Debian APT package management), unplug the router and then start looking for connections!
To have an automatic connection at boot up, maybe the easiest way is to write a little script, to be executed at the end of the init process (remember to tune it to your network's needs!):
root@OpenWrt:/# echo "ifconfig br0 192.168.1.199 up ;" > /etc/init.d/S99lanconnect root@OpenWrt:/# echo "route add default gw 192.168.1.1 br0 ;" >> /etc/init.d/S99lanconnect root@OpenWrt:/# echo "route del default gw 192.168.1.1 eth1 ;" >> /etc/init.d/S99lanconnect root@Openwrt:/# echo "echo \"nameserver 192.168.1.1\" > /etc/resolv.conf ;" >> /etc/init.d/S99lanconnect root@OpenWrt:/# echo "echo \"nameserver 80.58.32.97\" >> /etc/resolv.conf" >> /etc/init.d/S99lanconnect
Now we have a small script,/etc/init.d/S99lanconnect, telling the WRT that it's lan IP is 192.168.1.199, the lan gateway and main DNS is 192.168.1.1, and telling the WRT not to use the default wireless gateway. remember to tune this settings to the LAN connection you are going to use! Maybe your lan gateway isn't 192.168.1.1!
Change permissions for this script and restart the WRT, with an ethernet cable plugged to the LAN with internet connection
root@OpenWrt:/# chmod 755 /etc/init.d/S99lanconnect root@Openwrt:/# reboot
Now, from a computer connected in the LAN with a working internet connection, ssh into the WRT (this time responding at 192.168.1.199:
user@yourcomputer:# ssh 192.168.1.199
There you are back in your WRT. Now we will update the list of packages and install some interesting and helpful programs! There are hundreds of installable packages in OpenWRT, but don't forget that the disk space is very reduced on your machine!
root@OpenWrt:/# ipkg update Downloading http://downloads.openwrt.org/whiterussian/packages/Packages Updated list of available packages in /usr/lib/ipkg/lists/whiterussian Downloading http://downloads.openwrt.org/whiterussian/packages/non-free/Packages Updated list of available packages in /usr/lib/ipkg/lists/non-free Successfully terminated. root@OpenWrt:/# ipkg install wl kismet
There we are... from now on, typing "scan", we will get a list of the wireless connections running in the air around our WRT. Last step is to make the S99lanconnect script unexecutable, so that it will not be executed by default:
root@OpenWrt:/# chmod 444 /etc/init.d/S99lanconnect
Please read our legal warning before following these instructions !!!
with "iwconfig" we can survey the actual status of the wireless interface of the WRT:
root@OpenWrt:/# iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
eth1 IEEE 802.11-DS ESSID:""
Mode:Managed Frequency:2.462 GHz Tx-Power:19 dBm
RTS thr=2347 B Fragment thr=2346 B
Encryption key:off
vlan0 no wireless extensions.
vlan1 no wireless extensions.
While with "scan" you can scan your neighborhood for existing wifi connections: ("scan" is an alias of "wl scan ; sleep 1 ; wl scanresults"):
root@OpenWrt:/# scan
If your WRT gives no scan results, than move to another place or to the roof of your house. If the scanning has been succesfull you will see something like this ( Remember: press the MAIUSC key and PAGE UP to see the upper results):
SSID: "linksys" Mode: Managed RSSI: -95 dBm noise: -88 dBm Channel: 11 BSSID: 00:0F:66:D9:D6:1F Capability: ESS ShortSlot Supported Rates: [ 1(b) 2(b) 5.5(b) 11(b) 18 24 36 54 6 9 12 48 ] SSID: "Ajunta-miento" Mode: Managed RSSI: -98 dBm noise: -88 dBm Channel: 1 BSSID: 00:0F:21:6F:19:1A Capability: ESS WEP Supported Rates: [ 1(b) 2(b) 5.5(b) 11(b) 18 24 36 54 6 9 12 48 ] SSID: "default" Mode: Managed RSSI: -94 dBm noise: -88 dBm Channel: 1 BSSID: 00:01:36:0A:B2:1D Capability: ESS ShortPre ShortSlot Supported Rates: [ 1(b) 2(b) 5.5(b) 11(b) 6 9 12 18 24 36 48 54 ] SSID: "Wireless" Mode: Managed RSSI: -83 dBm noise: -88 dBm Channel: 1 BSSID: 00:A0:C5:83:C7:3E Capability: ESS Supported Rates: [ 1(b) 2(b) 5.5(b) 11(b) ] SSID: "Ipay4ya" Mode: Managed RSSI: -92 dBm noise: -89 dBm Channel: 6 BSSID: 00:C0:49:E0:68:7A Capability: ESS ShortPre PBCC ShortSlot Supported Rates: [ 1(b) 2(b) 5.5(b) 11(b) 22 6 9 12 18 24 36 48 54 ]
here we received a lot of informations we need about wireless networks on air:
First of all, look at the capability: if it says WEP or WPA or some oscure settings, than we will not be able to connect (search on the internet for "aircrack-ng", you can download it on a Openwrt); the rest of the channels are open, these are the channels we will try to connect to. Now look at the RSSI: if it's lower than 90 (89 is also good!), it means the signal we are receveing is enough strong, otherwise we are too far away or something is obstaculizing the connection (plastic do not stops the waves, wall and metals do!). Let's try to connect: (just type: "wl join", and the SSID of where you whant to connect)
root@OpenWrt:/# wl join Wireless
If jou joined the connection, than your iwconfig has changed. If it was not succesful, than your iwconfig has not changed: scan and try to join again a channel. Let's have a look at "iwconfig":
root@OpenWrt:/# iwconfig lo no wireless extensions. eth0 no wireless extensions. eth1 IEEE 802.11-DSF ESSID:"Wireless" Mode:Managed Channel:10 Access Point: 00:A0:C5:98:F2:95 Bit Rate:5.5Mb/s Tx-Power=15 dBm Retry limit:0 RTS thr:off Fragment thr:off Encryption key:off Link Quality:1/5 Signal level:-89 dBm Noise level:-256 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 vlan0 no wireless extensions. vlan1 no wireless extensions
As you can see, we succesfully connected: the ESSID has changed to the one we wanted to join, and we do have a link quality (from 0/5 to 5/5).
Now that we joined the wireless connection, we still have to join the LAN network. We can try to connect via DHCP or by manual IP configuration.
root@OpenWrt:/# udhcp -i eth1
Manual configuration: this is done with IP numbers, which are the addresses of the computers. Usually the number of your neighbour's router is a standard one: 192.168.1.1, but it could be different: 192.168.0.1, 192.168.2.1, 10.0.0.1. That means different network broadcasts: if your neighbour's router is 192.168.1.1 than we must be 192.168.1.something to reach it (ex. 192.168.1.77, 192.168.1.178, ...); if the IP is 192.168.2.1 than we must be 192.168.2.something. Let's try: give your computer an ip number for the wifi interface (use number between 51 and 99 or between 151 and 199)
root@OpenWrt:/# ifconfig eth1 192.168.1.77 up
Now let's try to contact your neighbour's router (stop pinging with "control-C"):
root@OpenWrt:/# ping 192.168.1.1
If the answer was "network not reacheable", than change with "ifconfig" your ip number to 192.168.0.77 or to 192.168.2.77, or to 10.0.0.77 or to 10.0.1.77 and ping the number 1 in the same network broadcast: 192.168.0.1, 192.168.2.1, 10.0.0.1, 10.0.1.1). If nothing is working, than change your wifi connection...
If the ping succeded, than the result will be something like this:
PING 192.168.1.1 (192.168.1.1): 56 data bytes 64 bytes from 192.168.1.1: icmp_seq=0 ttl=254 time=3.2 ms 64 bytes from 192.168.1.1: icmp_seq=1 ttl=254 time=2.9 ms 64 bytes from 192.168.1.1: icmp_seq=2 ttl=254 time=2.8 ms 64 bytes from 192.168.1.1: icmp_seq=3 ttl=254 time=2.9 ms 64 bytes from 192.168.1.1: icmp_seq=4 ttl=254 time=7.4 ms
Ok, we are exchanging informations with our neighbour's router. Now we will tell our WRT to use our neighbour's router as a gateway to the internet:
root@OpenWrt:/# route add default gw 192.168.1.1 eth1 root@OpenWrt:/# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.1.0 * 255.255.255.0 U 0 0 0 eth1 192.168.99.0 * 255.255.255.0 U 0 0 0 vlan0 default 192.168.1.1 0.0.0.0 UG 0 0 0 eth1
Let's try to ping an address in the internet:
root@OpenWrt:/# ping 141.20.1.3
If you don't get any response, something is wrong or your neighbours are not connected to the internet, so, try with another wifi connection. If you had a response, than let's go to the last step: see if the domain names (www.google.com, www.squat.net, ...) are successfully translated in IP numbers:
root@OpenWrt:/# ping heise.de
If you get a response, you're in, welcome to the OpenWrt wardriving team! If you don't get any response, then you need to change the "/etc/resolv.conf" file. This tells your machine which machine is doing the domain name resolution (DNS) for you. in the resolv.conf file there should be the IP number of your neighbour's router. just put it in. You can write typing the "i" key, to exit and save press "ESC", ":" and "x"
root@OpenWrt:/# vi /etc/resolv.conf
If you cannot save the file, than it's because it's not a real file, but just a link: remove it and write a new one:
root@OpenWrt:/# rm /etc/resolv.conf root@OpenWrt:/# vi /etc/resolv.conf
Here there is an example of a working "resolv.conf" file for Barcelona:
nameserver 192.168.1.1 #commercial servers nameserver 80.58.32.97 nameserver 194.224.52.37 #ORSN public servers nameserver 217.146.139.5 nameserver 62.157.101.211
Now that you have an internet connection, remember that your WRT's is already running a DHCP service for your internal LAN (look in "/etc/dnsmasq.conf" on the WRT), or if you want to configure your computers manually, the WRT's IP number should be the GATEWAY AND DNS for your computer, so in linux you will have to cahnge the route of your computer adding the WRT IP number as gateway, and you should change the /etc/resolv.conf putting your WRT IP number as a nameserver (you can just add it); in windows, in the properties of the connections, there is TCP/IP, open it, put the WRT IP number as gateway and also as DNS (the submask should be 255.255.255.0)
----------------------------- last update: otmmto 1/6/2007