Networking at home

I have a relatively complicated network setup at home and wanted to create a frontend to them, where I can easily switch on/off the servers, manage the server and router configurations, see if the internet is up and running ans see how many client computers are connected. After evaluating some options I conluded to use an AJAX based solution, running on the Ericsson W25 3G router. The idea was to have a schematic diagram showing all the computers on the newtork, with buttons on the computers to do management tasks. So here is the result: As you can see there are boxes for al routers and computers, with the power button you can swicth on or off the servers or restart the internet connection. With the setup button you can go to the management web interface for the servers or routers. In the bottom of the picture you see the clients who have got IP address, their status is checked with arping, so even with a switched on firewall you can see the status. In the information field for the ser...

On their support forum http://fwt.ericsson.net/ Ericcson made available the Administation manual which also includes the passwords needed to get root access to the 3G router. This gives the possiblility for every owner, to get access to the Linux inside the box, and do some customization like DynDNS, WEB server, speed tests automatic restarts and more.

I like very much custom firmware and altrough I have very little experience with it, I like very much reading about it. So here is a list of links to different custom firmware sites: Firmware for MP3 players - RockBox Firmware for Canon cameras - CHDK Firmware for Western Digital Media Players - B-RAD Firmware for Asus O!Play Media Players - MiniModding Firmware for Samsung TVs - SamyGo Firmware for Raidsonic NAS-1000/NAS-2000 NAS devices - NAS2000.org Firmware for routers: DD-WRT OpenWRT Tomato firmware Freetz for AVM FritzBox

I have created a list of the available command in the W25. Most commands give you a short help if you invoke them with the -h parameter, but where I have found, I have added a link to the description of the command. Unfortunately this is from an older SW relese R6A019, but still most of the comands are valid: List of Ericsson W25 linux comands Where you see that the size of the file is 515908 these are the BusyBox commands.

After a lot of unsuccessfull experiments, finally I could manage to send out a Wake On LAN magic packet from the W25. The solution is not universal, because I rely on a second router on my home network, to respond to an outgoing TCP packet. The difficulty in WOL for the W25 is that I found only the netcat (nc) program suitable for sending out IP packets from the router and the version of nc implemented in the W25 doesn't support UDP packets. I have manually constructed a magic packet and saved it to a file. The command: nc router2 80 < wakecode.bin sends this packet the the second routers which silenlty ignores it, because this is not a valid HTTP request. But there is still a problem, that in a swicthed LAN this traffic reaches only the second router and not the computer to be waked up. The solution for this is to play with the arp addresses and manually assign the broadcast ethernet addres to the second routers IP address: arp -s 192.168.1.107 ff:ff:ff:ff:ff:ff after waking up...

The firmware of the W25 doesn't support the handling of the SMS, but the bult in 3G modem does. So let's dig a bit into it and use this possibility. (In order to do this you need to have access to the command line of the W25). To control the modem of the W25 there are two commands to use: msctl - this is a high level handling with predefined command mctl - this is a low level command, which you can use to send AT command to the modem Try out: msctl rscp - this will give you the actual strength of your reception msctl issue ATI - this will give you information about the modem included in your device. Now if we would like to know, which AT commands we can use, we have to download the AT command book from the Sierra Wireless site: AT command reference . If this download will not work, just search the Sierre Wireless site for the AT command reference. When looking into this document, you will find a lot of interesting command, but you will soon realize that the command related to S...

After you have implemented the DynDNS for your W25 the next thing would be to have an external WEB server. As the W25 has a built in WEB server, it is only one line to start a web server. The command you should use is httpd . To start an external web server serving pages from the "web" directory of the connected Flash drive, issue the following command: httpd -i ppp0 -h /mnt/C2F8-E4F2/web This will start the web server from on the ppp0 interface, with the home directory being /mnt/C2F8-E4F2/web. The index file should be index.html. For all possible options to httpd issue httpd --help. To see the possibilities in the configuration file, go to the Busybox homepage and look at the examle coinfigutration file provided in the source for httpd.

Half year after the last publicly released SW version from 21st January there is a new SW version available on the official website. According my previous readings the 1.3 SW version solves some security issues, a memory leak in the WLAN driver and some minor issues. When I will get a better internet connection, I will download the new package and update this post with the exact details.

After using the W25 for some time I wanted to add a correct domain handling and certain new names to the DNS services offered by the router. Default behavior of the DNS system: The W25 uses the DNS server called DNRD which is a simple caching, forwarding DNS server, with the additional feature of being able to resolve names from /etc/hosts file. This is used in the original SW to add every local client after requesting an address trough DHCP. The updating of the hosts file is done by the script /bin/updatehostsfile which in is called by the script /etc/udhcpd/udhcpdnotify. The name of the script to be called by the dhcp daemon is specified in /etc/udhcpd.conf. Handling your internal domain with the W25: To handle your internal domain correctly you need to do the following: Add your local domain to the DHCP messages Create an updated "updatehostfile" script to include your domain names and fix addresses to the /etc/hosts file Change the dhcpd configuration to call your update...

Earlier I had speed problems with my unit and I wanted to make sure if it is only perception or if it is a real speed problem. The concept what I have implemented was, that the unit should make a test every 15 minutes to check the download speed of the cellular connection. Then the result with some other relevant information is added to a file stored on the external USB flash drive. So here is the script: wget -q -O /dev/null http://www.ericssonw25.com/pdf/w25_V1.2_R6A019.zip & wget -q -O /dev/null http://www.ericssonw25.com/pdf/W25_Users_Guide_D.pdf & wget -q -O /dev/null http://www.ericssonw25.com/pdf/W25_Users_Guide_C.pdf & sleep 3; bejovo=`cat /proc/net/dev |grep ppp0 |cut -d":" -f2 |awk '{print$1}'`; sleep 5; bejovo1=`cat /proc/net/dev |grep ppp0|cut -d":" -f2 |awk '{print$1}'`; kill `pidof wget` echo `date '+%Y.%m.%d %H:%M'` `echo $bejovo $bejovo1 |awk '{print (($2-$1))/640}'` kbps `msctl rscp...

By analysing the /bin/swinst script it become clear, that the firmware package is a simple tar file, containing the software components to be upgraded. Usually it contains the following elements: metainfo - detailed information and MD5 summs of the components to be installed preinstall.sh - script to be executed before installing postinstall.sh - script to be executed after installation zImage - linux kernel rootfs.squahfs - root file system wanbl - wan module boatloader wanfw - wan module firmware The swinst script is quite complex, but basicly it download the firmware form the internet to the TMP directory, checks the checksums, checks the SW versions and if the upgrade is needed, the upgrades first the main firmware, then the WAN bootloader and then the WAN firmware. When installing the main firmware it increases the number used by RedBoot boot loader, this way it is garanteed, that on restart the new version will boot. On the other hand, if the installation is interrupted, the old ...

Using the default ip network based time sycronization has two disadvantages: As you can not set time zones your device will run always on GMT In the current SW version the ntp daemon is crasing after some days so you will loose syncronization You can change it to cellular based syncronization with the following commands on the command line interface: # cf set sntp.enabled false # cf set cellular.celltime true # cf commit This will use your local time and will run forever. I have implemeted this 2 days ago, but it turned out that you can use this only if you have good enough coverage, othervise you will not get the time from the cellular network. So I swicthed back to the ip network based syncronization and I will write a script to periodically restart the time syncronization process.

I have spent some hours trying to find a propper source to get prebuilt binary files to be executed on the Ericsson W25 without sucess. I could figure out that I need "armeb" type files and I have found them in the Debian ARM packages and in OpenWRT kamikaze version, but none of them was usefull as the debian used a different version of the main c libraries and OpenWRT uses uLibC. If anyone know more sources of ready made binaries, please let me know.

Dynamic DNS is a technology used to have a permanent address even if your ip address is changing all the time. To do this you have to register at one of the Dynamic DNS providers (I have used no-ip.com ), select a nice web address for yoursef (e.g. kiki.no-ip.info) update your ip address and access your computer on this new address (kiki.no-ip.info). The update of your ip address can be done automatically by this simple script. The script checks your IP address and if it is changed it simply request the https page defined for updating your ip address. You can find this address for other DynDNS providers in their developer documentation. When requesting the update, you even don't have to include your IP address as the server will see it from the request. #!bin/sh IP=`ifconfig ppp0 |grep "inet addr" |awk '{print $2}' |awk -F: '{print $2}'`; if [ ! -e /var/tmp/oldip ] ; then OLDIP="1"; else OLDIP=`cat /var/tmp/oldip`; fi; if [ $IP = $OLDIP ] ; ...

Update: In the SW version 1.3 you can simply put your init scripts to /rw/etc/init.d/rc.local and do not need this complicated method. If we want our extra changes remain after restarting the Ericsson W25 we need to reapply them after restarting the router again. Normally this is done by a custom init script which makes the necessary changes for us. In the W25 we need to do some special tricks to be able to start our own script as most of the /etc directory and the complete /etc/init.d is in a read only filesystem. However we are clever guys and we notice that the /etc/ppp/peers directory is in the rw filesystem and we know that for the pppd we can give a dialer program as a parameter. Let's use this for starting our own init script, when the unit first tries to connect to the 3G network. We have to change the following line in /etc/ppp/peers/3g: connect "/usr/sbin/chat -V -f /etc/ppp/chat/3g-connect" to the following: connect "/root/lchat -V -f /etc/ppp/chat/3g-co...

The Ericsson W25 is running an embebbed linux. When you power on your device first the bootloader is started. The bootloader is responsible for loading in the complete operating system and start it up. In the Ericsson W25 there is a RedBoot bootloader , which has plenty of features. It is capable of booting from network, from serial devices, it has a telnet interface etc., but in our case it just selects the propper linux kernel and the propper root file system and starts up the linux operating system. All the software to be loaded is stored in the built in ROM, in 9 partitons: 0x00000000-0x00080000 : "RedBoot" 0x00080000-0x001c0000 : "kernel_A" 0x001c0000-0x007a0000 : "rootfs_A" 0x007a0000-0x008e0000 : "kernel_B" 0x008e0000-0x00ec0000 : "rootfs_B" 0x00ec0000-0x00fa0000 : "rwfs" 0x00fa0000-0x00fe0000 : "test" 0x00fe0000-0x00fff000 : "FIS directory" 0x00fff000-0x01000000 : "RedBoot config" As you c...

Before looking at the hardware of the Ericsson W25, I would like to emphasize once more the importance of changing your passwords in the router. This morning I found very nice traces of an attack against my router in the logs: Oct 30 08:31:37 (none) auth.err sshd[9534]: error: Could not get shadow information for root Oct 30 08:31:37 (none) auth.info sshd[9534]: Failed password for root from 220.90.216.15 port 60418 ssh2 Oct 30 08:31:41 (none) auth.info sshd[9536]: Illegal user andrew from 220.90.216.15 O ct 30 08:31:41 (none) auth.err sshd[9536]: error: Could not get shadow information for NOUSER Oct 30 08:31:41 (none) auth.info sshd[9536]: Failed password for illegal user andrew from 220.90.216.15 port 60649 ssh2 and this went on for 900 more lines. Apparently someone was trying to log into my router by trying out username/password pairs. The original Ericsson password for root is so easy, that probably the attacker would have succeeded. But, now lets turn to the HW: It is based on t...

The first step if you want more from your Ericsson W25 is to gain access to its command line interface. The command line interface (CLI in the future) can be accessed over the network either by telnet or ssh protocol. Telnet is available only from within your local network, and for accessing it you can use the telnet command built into Windows: telnet 192.168.1.1 The ssh access is available both from the internal network and from the internet and you should use an ssh client like PuTTY to access it. There are two user names available for the CLI: root and operator . You can find their default password in the document about SW upgrade on http://www.mobiledata.net.au/ . Once you have logged in, you find yourself in a linux environment. Linux commands like ls, pwd, mount etc. will work. There are two specific commands for the router: cf and st . The cf command is used to set and retrieve the parameters of the router. When called without parameters it gives a help about the available c...

A fixed wireless router means a device which is connected to the internet using a mobile network and it distributes the internet access for a home/small office network using wired and/or wireless LAN. The reason for using this kind of devices is either because where you live/work you do not have a fixed internet or simply because the price for a mobile internet can be lower than for a fixed one. The Ericsson W25 is a GSM/UMTS/HSDPA one, it can be used on GSM or UMTS networks. The theoretical maximal donwload speed is, 7.2 Mbit/sec with HSDPA, but today only very few carriers support this and even if it is supperted you can not reach this speed. The network which I am using supports only 1,8 Mbit/sec where I live and even with this theoretical possibility I can not reach higher speed than 1,4 Mbit/sec. However this speed is almost 3 times higher than my previous internet connection which was an outdoor WLAN based 512 k connection. Beside the internet access this device has the possibili...

Altough networking is used more when people are getting connected, in my case this is about computer networks at home. What you can expect here are some rather technical articles about what I have done or what I wanted to do in my home LAN. The first blogs will be about the Ericsson W25 router which is a mobile network to WLAN router.