Background

I was with my geekfriends at a ski resort and I managed to get an Internet connection using a cellphone. Of course I wanted to share it with my friends. As geeks we brought a switch and a couple of ethernetcables.

Solution

Using this script on a Ubuntu 9.10 I managed to share my connection:

sudo ifconfig eth0 10.8.16.1
sudo sysctl -w net.ipv4.ip_forward=1
sudo sysctl -w net.ipv4.conf.default.forwarding=1
sudo sysctl -w net.ipv4.conf.all.forwarding=1
sudo iptables -P FORWARD ACCEPT
sudo iptables --table nat -A POSTROUTING -o ppp0 -j MASQUERADE

Conmnect everymachine with the switch and the clients just needed to use a 10.0.0.0/8 network adress and add 10.8.16.1 as default gateway and it works!

After some Google search and reading of man pages I finally get it working.

My setup is a Nokia E52 and a IBM T60 laptop running Ubuntu 9.10. I have tested it with a Ericsson P1i and a Dell D630 aswell and I think the guidlines below will work with many other setups. One exception is probably iPhone

From a bash shell run:

peter@svarten:~$ sdptool search DUN
Inquiring ...
Searching for DUN on A8:7E:33:20:40:0F ...
Service Name: Dial-Up Networking
Service RecHandle: 0x10030
Service Class ID List:
  "Dialup Networking" (0x1103)
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 5
Language Base Attr List:
  code_ISO639: 0x454e
  encoding:    0x6a
  base_offset: 0x100
Profile Descriptor List:
  "Dialup Networking" (0x1103)
    Version: 0x0100

peter@svarten:~$ sudo rfcomm connect 1 A8:7E:33:20:40:0F 5
[sudo] password for peter:
Connected /dev/rfcomm1 to A8:7E:33:20:40:0F on channel 5
Press CTRL-C for hangup

Now my phone asks if I accept the connection and I choose "yes".

And now the networkmanager has a new "Mobile Broadband connection". Just choose your operator and it will work.

To start a script in the default run levels:

sudo update-rc.d appname defaults

To remove a script from all runlevels:

sudo update-rc.d appname remove

The more logical name gives date and title of the blog post instead of a cryptic number. Changing from one to another is rather simple, just change it in the wordpress settings, but there is several drawbacks:

• Referers stop working, if someone is refering to your pages they will stop working until someone updates the link
• Search engines will refer to the wrong page until the pages are indexed again and very likely the rank will drop
• Wordpress internal references will stop working, so the mainpage links will stop working. This is real stupid and I do not understand why Wordpress behaves like this.

The solution is to install the plugin  "Permalinks Moved Permanently" which fixes this problem, make sure that the webserver allows rewrite.

Links

• The plugin used Permalinks Moved Permanently
• A webpage describing howto enable mod_rewrite for Ubuntu Server.

Just run:

sudo apt-get install ubuntu-restricted-extras
sudo apt-get install libstdc++5

and now it works perfectly well.

In an earlier article I have described howto set it up on RHES or CentOS, it is slightly different in Ubuntu.

1.Installation

root@ibsen:~# sudo apt-get install snmpd
Reading package lists... Done
Building dependency tree      
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libmpich1.0gf libdc1394-22 genisoimage linux-headers-2.6.27-7 libgfortran2 dvd+rw-tools linux-headers-2.6.27-7-generic libcarp-clan-perl libxml-xql-perl libparse-yapp-perl
  rdate python-xml localechooser-data gcc-4.2-base libimage-size-perl libdebconfclient0 libvisual-0.4-0 libmyth-python perlmagick libvisual-0.4-plugins libavdevice52
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  libperl5.10 libsensors3 libsnmp-base libsnmp15
Suggested packages:
  lm-sensors
The following NEW packages will be installed:
  libperl5.10 libsensors3 libsnmp-base libsnmp15 snmpd
0 upgraded, 5 newly installed, 0 to remove and 3 not upgraded.
Need to get 2463kB of archives.
After this operation, 7987kB of additional disk space will be used.
Do you want to continue [Y/n]? 

answer y

2. Configuration

Move existing /etc/snmp/snmpd.conf configuration file to /etc/snmp/snmpd.conf.org

mv /etc/snmp/snmpd.conf  /etc/snmp/snmpd.conf.org

Create a new /etc/snmp/snmpd.conf file:

rocommunity  public
syslocation  "PDC, Peters DataCenter"
syscontact  peter@it-slav.net

Make snmpd use the newly created file and make it listen to all interfaces:

Edit /etc/default/snmpd

Change from:

# snmpd options (use syslog, close stdin/out/err).
SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid 127.0.0.1'

To:

# snmpd options (use syslog, close stdin/out/err).
#SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid 127.0.0.1'
SNMPDOPTS='-Lsd -Lf /dev/null -u snmp -I -smux -p /var/run/snmpd.pid -c /etc/snmp/snmpd.conf'

and restart snmpd

/etc/init.d/snmpd restart

3. Test

Do a snmpwalk from another host against your newly configured host.

[root@op5 ~]# snmpwalk -v 1 -c public -O e ibsen
SNMPv2-MIB::sysDescr.0 = STRING: Linux ibsen 2.6.27-9-generic #1 SMP Thu Nov 20 21:57:00 UTC 2008 i686
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.10
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (68869) 0:11:28.69
SNMPv2-MIB::sysContact.0 = STRING: peter@it-slav.net
SNMPv2-MIB::sysName.0 = STRING: ibsen
SNMPv2-MIB::sysLocation.0 = STRING: "PDC, Peters DataCenter"
SNMPv2-MIB::sysORLastChange.0 = Timeticks: (1) 0:00:00.01
SNMPv2-MIB::sysORID.1 = OID: SNMP-FRAMEWORK-MIB::snmpFrameworkMIBCompliance
SNMPv2-MIB::sysORID.2 = OID: SNMP-MPD-MIB::snmpMPDCompliance
SNMPv2-MIB::sysORID.3 = OID: SNMP-USER-BASED-SM-MIB::usmMIBCompliance
SNMPv2-MIB::sysORID.4 = OID: SNMPv2-MIB::snmpMIB
SNMPv2-MIB::sysORID.5 = OID: TCP-MIB::tcpMIB
SNMPv2-MIB::sysORID.6 = OID: IP-MIB::ip

Yes it works!!

4. Monitor example

Below is an example of how it looks using op5 Monitor a Nagios based Enterprise Monitor solution.

5. Useful links

• op5 Statistics, a cacti based graph tool
• op5 Monitor, an Enterprise Class Monitoring system based on Nagios
• Net-SNMP, an open source implementation of SNMP
• Cacti, an open source graph tool
• Nagios, the number 1 monitor tool

Start

To configure the newly installed MythTV system run:

mythtv-setup

The settings will we be default if nothing else is mentioned.

1. General settings

In general settings change the Ip-adress from 127.0.0.1 to the real ip-adress. This makes it possible for a frontend system on the network to communicate with with the backend.

Security PIN: 0000 (means no security)

TV format: choose the one you have, in my case PAL-BG

Channel frequency table: europe-west

2.Capture cards

This is were the TV card is configured. I did the mistake to use v4l Hauppgage PVR-350 driver which was the suggested driver. That did not work. Use MPEG Hauppgage PVR-350 driver instead where the builtin MPEG decoder will be used, thats why I could use such modest CPU PIII 800Mhz.

3. Video sources

When entering this menu, the mythtv system scans for grabbers. Unfortunately there is a timeout of 25 seconds and my hardware do not deliver the list of all grabbers in that time. The result is that no grabbers show up. The workaround is to move all the XMLTV grabbers to another directory except the one I will use:

cd /usr/bin

sudo mkdir tv_grabbackup/

sudo mv tv_grab_* tv_grabbackup/

sudo mv tv_grabbackup/tv_grab_se_swedb .

Name a new grabber i.e. Sweden and next.

Now the MythTV system appear to hang but with alt-tab you can change to a newly open terminal window.

Answer yes to all the channels you have.

In my case I found a list at http://www.comhem.se/ and it looked like this:

4. Input connections

Choose the correct input hardware to the grabber, in my case:

MPEG: /dev/video0 (Tuner1) -> Sweden

5. Channel editor

I managed to get my MythTV system to scan all the frequenses. The list created was not in the same format as the list from my Cable TV provider.

After analysing the list I figured out that the following channelnumbers matched the list above:

Kanal 5  SE11

Kanal 9  S36

MTV      SE16

TV4 Plus   SE14

TV4Sport  SE17

SVT1  E5

SVT2   E7

SVT 24   E10

SVT Kunskapskanalen/Barnkanalen   SE13

TV3   E11

TV4   E6

TV6   E8

Go in to every channel and enter the channelnumber.

6.Storage Directories

I did not change anything here

Wrap it up

After configured the mythtvbackend, run:

mythfilldatabase –manual

Answer default to all of the questions.

MySQL access from the frontend to the backend

The frontend must be able to access the MySQL running at the backend. To provide that run the following commands:

mysql -u root mythconverg
mysql> grant all on mythconverg.* to mythtv@”%” identified by “mythtv”;
mysql> flush privileges;

Note: This will let any machine have access to your MythTV database and should only be used in a controlled environment.

Congratulations, now you have configured your MythTV backend system.

Next step will be configure the Xbox frontend.

The Backend hardware:

• IBM Desktop
• PIII 800Mhz
• 512 Mb memory
• 120 Gb disk
• Hauppauge PVR-350

The frontend hardware is an old Xbox, with XBMC.

I downloaded Mythbuntu and installed it on the MythTV backend system.

During boot my TV card was detected and the firmware was loaded, last time this took several nights to understand.

dmesg gives:

--snipp--
[   18.764273] Linux video capture interface: v2.00
[   19.191631] ivtv:  Start initialization, version 1.4.0
[   19.191999] ivtv0: Initializing card #0
[   19.192060] ivtv0: Autodetected Hauppauge card (cx23415 based)
[   19.245036] ivtv 0000:01:0d.0: enabling device (0000 -> 0002)
[   19.245073] ivtv 0000:01:0d.0: PCI INT A -> GSI 21 (level, low) -> IRQ 21
[   19.245098] ivtv 0000:01:0d.0: setting latency timer to 64
[   19.299891] tveeprom 0-0050: Hauppauge model 48134, rev J347, serial# 2756181
[   19.299905] tveeprom 0-0050: tuner model is LG TP18PSB01D (idx 47, type 28)
[   19.299915] tveeprom 0-0050: TV standards PAL(B/G) (eeprom 0x04)
[   19.299925] tveeprom 0-0050: audio processor is MSP4418 (idx 25)
[   19.299935] tveeprom 0-0050: decoder processor is SAA7115 (idx 19)
[   19.299944] tveeprom 0-0050: has radio, has IR receiver, has no IR transmitter
[   19.299954] ivtv0: Autodetected Hauppauge WinTV PVR-350

--snip--

[   21.864260] saa7127 0-0044: saa7127 found @ 0x88 (ivtv i2c driver #0)
[   21.888601] msp3400 0-0040: MSP4418G-A2 found @ 0x80 (ivtv i2c driver #0)
[   21.888614] msp3400 0-0040: msp3400 supports nicam and radio, mode is autodetect and autoselect
[   21.898458] tuner 0-0061: chip found @ 0xc2 (ivtv i2c driver #0)
[   22.203952] tuner-simple 0-0061: creating new instance
[   22.203968] tuner-simple 0-0061: type set to 28 (LG PAL_BG+FM (TPI8PSB01D))
[   22.217306] ivtv0: Registered device video0 for encoder MPG (4096 kB)
[   22.217591] ivtv0: Registered device video32 for encoder YUV (2048 kB)
[   22.217780] ivtv0: Registered device vbi0 for encoder VBI (1024 kB)
[   22.217962] ivtv0: Registered device video24 for encoder PCM (320 kB)
[   22.218140] ivtv0: Registered device radio0 for encoder radio
[   22.218319] ivtv0: Registered device video16 for decoder MPG (1024 kB)
[   22.218489] ivtv0: Registered device vbi8 for decoder VBI (64 kB)
[   22.218661] ivtv0: Registered device vbi16 for decoder VOUT
[   22.218875] ivtv0: Registered device video48 for decoder YUV (1024 kB)
[   22.218886] ivtv0: Initialized card #0: Hauppauge WinTV PVR-350
[   22.220588] ivtv:  End initialization
--snipp--

[   46.100093] firmware: requesting v4l-cx2341x-enc.fw
[   46.423446] ivtv0: Loaded v4l-cx2341x-enc.fw firmware (376836 bytes)
[   46.423590] firmware: requesting v4l-cx2341x-dec.fw
[   46.567632] ivtv0: Loaded v4l-cx2341x-dec.fw firmware (262144 bytes)
[   46.764454] ivtv0: Encoder revision: 0x02060039
[   46.764597] ivtv0: Decoder revision: 0x02020023
[   46.831434] firmware: requesting v4l-cx2341x-init.mpg
[   46.939513] ivtv0: Loaded v4l-cx2341x-init.mpg firmware (155648 bytes)

The next step is to configure my newly installed system.

I installed Ubuntu 8.10 Desktop x86_64 and had som problems with:

• Java based webpages
• Flash

I spend several hours with google and tested several versions av java and flash plugins. I managed to get flash running but it was incredible unstable and java never worked. Both were installed as 32 bit applications.

I reinstalled and used Ubuntu 8.10 Desktop i386 instead and went to a flash page and installed acrobat flash player plugin from the suggestions that poped up and the same with java. It worked perfectly well.

We run WebEx as a conference application at op5 and they say that any day they will have a Linux 32 bit client, so that is another reason to use 32 bit Linux. Otherwise I have to install a virtual windows just for one application.

This really show why interoperability is important and why open standards should be used. As far as I understand Java is GPLd these days so why a 64 bit version does not exist is something I do not understand or if it exist why did it install a 32 bit version? Why does not Acrobat release their flashplayer as opensource?

Well, now I’m stucked with using only 3.6 Gb of memory but the application works.

I found an excellent how to get it running at:

http://bayanijuan.blogspot.com/2007/09/howto-connect-to-internet-using-se.html

It will work with several phones and many Linux flavors.