Posts Tagged ‘connection’

Mount remote Linux SSHFS Filesystem harddisk on Windows Explorer SWISH SSHFS file mounter and a short evaluation on what is available to copy files to SSHFS from Windows PC

Monday, February 22nd, 2016

swish-mount-and-copy-files-from-windows-to-linux-via-sshfs-mount

I'm forced to use Windows on my workbook and I found it really irritating, that I can't easily share files in a DropBox, Google Drive, MS OneDrive, Amazon Storage or other cloud-storage free remote service. etc.
I don't want to use DropBox like non self-hosted Data storage because I want to keep my data private and therefore the only and best option for me was to make possible share my Linux harddisk storage
dir remotely to the Windows notebook.

I didn't wanted to setup some complex environment such as Samba Share Server (which used to be often a common option to share file from Linux server to Windows), neither wanted to bother with  installing FTP service and bother with FTP clients, or configuring some other complex stuff such as WebDav – which BTW is an accepted and heavily used solution across corporate clients to access read / write files on a remote Linux servers.
Hence, I made a quick research what else besides could be used to easily share files and data from Windows PC / notebook to a home brew or professional hosting Linux server.

It turned out, there are few of softwares that gives a similar possibility for a home lan small network Linux / Windows hybrid network users such, here is few of the many:

  • SyncThingSyncthing is an open-source file synchronization client/server application, written in Go, implementing its own, equally free Block Exchange Protocol. The source code's content-management repository is hosted on GitHub

     

     

     

     

     

    syncthing-logo

  • OwnCloud – ownCloud provides universal access to your files via the web, your computer or your mobile devices

     

     

     

     

     

    owncloud-logo

  • Seafile – Seafile is a file hosting software system. Files are stored on a central server and can be synchronized with personal computers and mobile devices via the Seafile client. Files can also be accessed via the server's web interface


seafile-client-in-browser

I've checked all of them and give a quick try of Syncthing which is really easy to start, just download the binary launch it and configure it under https://Localhost:8385 URL from a browser on the Linux server.
Syncthing seemed to be nice and easy to configure solution to be able to Sync files between Server A (Windows) and Server B(Linux) and guess many would enjoy it, if you want to give it a try you can follow this short install syncthing article.
However what I didsliked in both SyncThing and OwnCloud and Seafile and all of the other Sync file solutions was, they only supported synchronization via web and didn't seemed to have a Windows Explorer integration and did required
the server to run more services, posing another security hole in the system as such third party softwares are not easily to update and maintain.

Because of that finally after rethinking about some other ways to copy files to a locally mounted Sync directory from the Linux server, I've decided to give SSHFS a try. Mounting SSHFS between two Linux / UNIX hosts is
quite easy task with SSHFS tool

In Windows however the only way I know to transfer files to Linux via SSHFS was with WinSCP client and other SCP clients as well as the experimental:

As well as few others such as ExpandDrive, Netdrive, Dokan SSHFS (mirrored for download here)
I should say that I first decided to try copying few dozen of Gigabyte movies, text, books etc. using WinSCP direct connection, but after getting a couple of timeouts I was tired of WinSCP and decided to look for better way to copy to remote Linux SSHFS.
However the best solution I found after a bit of extensive turned to be:

SWISH – Easy SFTP for Windows

Swish is very straight forward to configure compared to all of them you download the .exe which as of time of writting is at version 0.8.0 install on the PC and right in My Computer you will get a New Device called Swish next to your local and remote drives C:/ D:/ , USBs etc.

swish-new-device-to-appear-in-my-computer-to-mount-sshfs

As you see in below screenshot two new non-standard buttons will Appear in Windows Explorer that lets you configure SWISH

windows-mount-sshfs-swish-add-sftp-connection-button-screenshot

Next and final step before you have the SSHFS remote Linux filesystem visible on Windows Xp / 7 / 8 / 10 is to fill in remote Linux hostname address (or even better fill in IP to get rid of possible DNS issues), UserName (UserID) and Direcory to mount.

swish-new-fill-in-dialog-to-make-new-linux-sshfs-mount-directory-possible-on-windows

Then you will see the SSHFS moutned:

swish-sshfs-mounted-on-windows

You will be asked to accept the SSH host-key as it used to be unknown so far

swish-mount-sshfs-partition-on-windows-from-remote-linux-accept-key

That's it now you will see straight into Windows Explorer the remote Linux SSHFS mounted:

remote-sshfs-linux-filesystem-mounted-in-windows-explorer-with-swish

Once setupped a Swish connection to copy files directly to it you can use the Send to Embedded Windows dialog, as in below screenshot

swish-send-to-files-windows-screenshot

The only 3 problem with SWISH are:

1. It doesn't support Save password, so on every Windows PC reboot when you want to connect to remote Linux SSHFS, you will have to retype remote login user pass.
Fron security stand point this is not such a bad thing, but it is a bit irritating to everytime type the password without an option to save permanently.
The good thing here is you can use Launch Key Agent
as visible in above screenshot and set in Putty Key Agent your remote host SSH key so the passwordless login will work without any authentication at
all however, this might open a security hole if your Win PC gets infected by virus, which might delete something on remote mounted SSHFS filesystem so I personally prefer to retype password on every boot.

2. it is a bit slow so if you're planning to Transfer large amounts of Data as hundreds of megabytes, expect a very slow transfer rate, even in a Local  10Mbit Network to transfer 20 – 30 GB of data, it took me about 2-3 hours or so.
SWISH is not actively supported and it doesn't have new release since 20th of June 2013, but for the general work I need it is just perfect, as I don't tent to be Synchronizing Dozens of Gigabytes all the time between my notebook PC and the Linux server.

3. If you don't use the established mounted connection for a while or your computer goes to sleep mode after recovering your connection to remote Linux HDD if opened in Windows File Explorer will probably be dead and you will have to re-enable it.

For Mac OS X users who want to mount / attach remote directory from a Linux partitions should look in fuguA Mac OS X SFTP, SCP and SSH Frontend

I'll be glad to hear from people on other good ways to achieve same results as with SWISH but have a better copy speed while using SSHFS.

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Check your Server Download / Upload Internet Speed from Console on Linux / BSD / Unix howto

Tuesday, March 17th, 2015

tux-check-internet-network-download-upload-speed-on-linux-console-terminal-linux-bsd-unix
If you've been given a new dedicated server from a New Dedicated-Server-Provider or VPS with Linux and you were told that a certain download speed to the Server is guaranteed from the server provider, in order to be sure the server's connection to the Internet told by service provider is correct it is useful to run a simple measurement console test after logging in remotely to the server via SSH.

Testing connection from Terminal is useful because as you probably know most of Linux / UNIX servers doesn't have a GUI interface and thus it is not possible to test Internet Up / Down Bandwidth through speedtest.net.
 

1. Testing Download Internet Speed given by ISP / Dedi-Server Provider from Linux Console

For the download speed (internet) test the historical approach was to just try downloading the Linux kernel source code from www.kernel.org with some text browser such as lynx or links count the seconds for which the download is completed and then multiple the kernel source archive size on the seconds to get an approximate bandwidth per second, however as nowdays internet connection speeds are much higher, thus it is better to try to download some Linux distribution iso file, you can still use kernel tar archive but it completed too fast to give you some good (adequate) statistics on Download bandwidth.

If its a fresh installed Linux server probably you will probably not have links / elinks and lynx text internet browers  installed so install them depending on deb / rpm distro with:

If on Deb Linuz distro:

 

root@pcfreak:/root# apt-get install –yes links elinks lynx

 

On RPM Based Linuz distro:
 

 

[root@fedora ~]# yum install -y lynx elinks links

 

Conduct Internet  Download Speed with links
root@pcfreak:/root# links https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.19.1.tar.xz

check_your_download_speed-from-console-linux-with-links-text-browser

(Note that the kernel link is current latest stable Kernel source code archive in future that might change, so try with latest archive.)

You can also use non-interactive tool such as wget curl or lftp to measure internet download speed

To test Download Internet Speed with wget without saving anything to disk set output to go to /dev/null 

 

root@pcfreak:~# wget -O /dev/null http://pc-freak.net/~hipo/hirens-bootcd/HirensBootCD15/Hirens.BootCD.15.0.zip

 

check_bandwidth_download-internet-speed-with-wget-from-console-non-interactively-on-linux

You see the Download speed is 104 Mbit/s this is so because I'm conducting the download from my local 100Mbit network.

For the test you can use my mirrored version of Hirens BootCD

2. Testing Uplink Internet speed provided by ISP / Server Provider from Linux (SSH) Console

To test your uplink speed you will need lftp or iperf command tool.

 

root@pcfreak:~# apt-cache show lftp|grep -i descr -A 12
Description: Sophisticated command-line FTP/HTTP client programs
 Lftp is a file retrieving tool that supports FTP, HTTP, FISH, SFTP, HTTPS
 and FTPS protocols under both IPv4 and IPv6. Lftp has an amazing set of
 features, while preserving its interface as simple and easy as possible.
 .
 The main two advantages over other ftp clients are reliability and ability
 to perform tasks in background. It will reconnect and reget the file being
 transferred if the connection broke. You can start a transfer in background
 and continue browsing on the ftp site. It does this all in one process. When
 you have started background jobs and feel you are done, you can just exit
 lftp and it automatically moves to nohup mode and completes the transfers.
 It has also such nice features as reput and mirror. It can also download a
 file as soon as possible by using several connections at the same time.

 

root@pcfreak:/root# apt-cache show iperf|grep -i desc -A 2
Description: Internet Protocol bandwidth measuring tool
 Iperf is a modern alternative for measuring TCP and UDP bandwidth performance,
 allowing the tuning of various parameters and characteristics.

 

To test Upload Speed to Internet connect remotely and upload any FTP file:

 

root@pcfreak:/root# lftp -u hipo pc-freak.net -e 'put Hirens.BootCD.15.0.zip; bye'

 

uploading-file-with-lftp-screenshot-test-upload-internet-speed-linux

On Debian Linux to install iperf:

 

root@pcfreak:/root# apt-get install –yes iperf

 

On latest CentOS 7 and Fedora (and other RPM based) Linux, you will need to add RPMForge repository and install with yum

 

[root@centos ~]# rpm -ivh  rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm

[root@centos ~]# yum -y install iperf

 

Once having iperf on the server the easiest way currently to test it is to use
serverius.net speedtest server –  located at the Serverius datacenters, AS50673 and is running on a 10GE connection with 5GB cap.

 

root@pcfreak:/root# iperf -c speedtest.serverius.net -P 10
————————————————————
Client connecting to speedtest.serverius.net, TCP port 5001
TCP window size: 16.0 KByte (default)
————————————————————
[ 12] local 83.228.93.76 port 54258 connected with 178.21.16.76 port 5001
[  7] local 83.228.93.76 port 54252 connected with 178.21.16.76 port 5001
[  5] local 83.228.93.76 port 54253 connected with 178.21.16.76 port 5001
[  9] local 83.228.93.76 port 54251 connected with 178.21.16.76 port 5001
[  3] local 83.228.93.76 port 54249 connected with 178.21.16.76 port 5001
[  4] local 83.228.93.76 port 54250 connected with 178.21.16.76 port 5001
[ 10] local 83.228.93.76 port 54254 connected with 178.21.16.76 port 5001
[ 11] local 83.228.93.76 port 54255 connected with 178.21.16.76 port 5001
[  6] local 83.228.93.76 port 54256 connected with 178.21.16.76 port 5001
[  8] local 83.228.93.76 port 54257 connected with 178.21.16.76 port 5001
[ ID] Interval       Transfer     Bandwidth
[  9]  0.0-10.2 sec  4.05 MBytes  3.33 Mbits/sec
[ 10]  0.0-10.2 sec  3.39 MBytes  2.78 Mbits/sec
[ 11]  0.0-10.3 sec  3.75 MBytes  3.06 Mbits/sec
[  4]  0.0-10.3 sec  3.43 MBytes  2.78 Mbits/sec
[ 12]  0.0-10.3 sec  3.92 MBytes  3.18 Mbits/sec
[  3]  0.0-10.4 sec  4.45 MBytes  3.58 Mbits/sec
[  5]  0.0-10.5 sec  4.06 MBytes  3.24 Mbits/sec
[  6]  0.0-10.5 sec  4.30 MBytes  3.42 Mbits/sec
[  8]  0.0-10.8 sec  3.92 MBytes  3.03 Mbits/sec
[  7]  0.0-10.9 sec  4.03 MBytes  3.11 Mbits/sec
[SUM]  0.0-10.9 sec  39.3 MBytes  30.3 Mbits/sec

 

You see currently my home machine has an Uplink of 30.3 Mbit/s per second, that's pretty nice since I've ordered a 100Mbits from my ISP (Unguaranteed Bandwidth Connection Speed) and as you might know it is a standard practice for many Internet Proviers to give Uplink speed of 1/4 from the ISP provided overall bandwidth 1/4 would be 25Mbi/s, meaning my ISP (Bergon.NET) is doing pretty well providing me with even more than promised (ordered) bandwidth.

Iperf is probably the choice of most sysadmins who have to do regular bandwidth in local networks speed between 2 servers or test  Internet Bandwidth speed on heterogenous network with Linux / BSDs / AIX / HP-UX (UNIXes). On HP-UX and AIX and other UNIXes for which iperf doesn't have port you have to compile it yourself.

If you don't have root /admin permissions on server and there is python language enterpreter installed you can use speedtest_cli.py script to test internet throughput connectivity
speedtest_cli uses speedtest.net to test server up / down link just in case if script is lost in future I've made ownload mirror of speedtest_cli.py is here

Quickest way to test net speed with speedtest_cli.py:

 

$ lynx -dump https://raw.github.com/sivel/speedtest-cli/master/speedtest_cli.py > speedtest_cli.py
$ chmod +x speedtest_cli.py
python speedtest_cli.py

speedtest_cli_pyhon_script_screenshot-on-gnu-linux-test-internet-network-speed-on-unix

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Fix MySQL connection error – Host ” is blocked because of many connection errors; unblock with ‘mysqladmin flush-hosts’

Wednesday, July 2nd, 2014

fix-mysql-too-many-connection-errors-explained

If you get a MySQL error like:

Host '' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'

This most likely means your PHP / Java whatever programming language application connecting to MySQL is failing to authenticate with the application created (existing) or that the application is trying too many connections to MySQL in a rate where MySQL server can't serve all the requests.

Some common errors for Too many Connection errors are:
 

  • Networking Problem
  • Server itself could be down
  • Authentication Problems
  • Maximum Connection Errors allowed.

The value of the max_connection_errors system variable determines how many successive interrupted connection requests are permitted to myqsl server.
 

Well anyways if you get the:

Host '' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'

You can consider this a sure sign application connections to MySQLis logging a lot of error connections, for some reason.
This error could also appear on very busy websites where high amount of separete connections are used – I've seen the error occur on PHP websites whether mysql_pconnect(); is selected in favour of the prooved working mysql_connect();

The first thing to do before changing / increasing default set of max connection errors is to check how many max connection errors are set within MySQL?

For that connect with MySQL CLI and issue:
 

mysql> SHOW VARIABLES LIKE '%error%';


+——————–+————————————————————-+
| Variable_name      | Value                                                           |
+——————–+————————————————————-+
| error_count        | 0                                                                     |
| log_error          | /var/log/mysql//mysqld.log                                |
| max_connect_errors | 10000                                                      |
| max_error_count    | 64                                                               |
| slave_skip_errors  | OFF                                                             |
+——————–+————————————————————-+


A very useful mysql cli command in debugging max connection errors reached problem is

mysql> SHOW PROCESSLIST;

 

To solve the error, try to tune in /etc/my.cnf, /etc/mysql/my.cnf or wherever my.cnf is located:

[mysqld]
max_connect_errors
variable

and

wait_timeout var. Some reasonable variable size would be:

max_connect_errors = 100000
wait_timeout = 60

If such (anyways) high values is still not high enough you can raise mysql config connection timeout

 

to

max_connect_errors = 100000000

Also if you want to try raise max_connect_errors var without making it permanenty (i.e. remember var setting after MySQL service restart), set it from MySQL cli with:

SET GLOBAL max_connect_errors


If you want to keep the set default max_connection_errors and fix it temporary, you can try to follow the error

Host '' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'

suggestion and issue in root console:

mysqladmin flush-hosts

Same could also be done from MySQL Cli with cmd:
 

FLUSH HOSTS;

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Create local network between virtual machines in Virtualbox VM – Add local LAN between Linux Virtual Machines

Wednesday, June 11th, 2014

add-virtualbox-virtual-machines-inside-local-network-create-internal-LAN-local-net-linux-windows

I want to do test MySQL Cluster following MySQL Cluster Install Guide for that purpose, I've installed 2 version of CentOS 6.5 inside Virtualbox and I wanted to make the 2 Linux hosts reachable inside a local LAN network, I consulted some colleagues who adviced me to configure two Linux hosts to use Bridget Adapter Virtualbox networking (Network configuration in Virtualbox is done on a Virtual Machine basis from):
 

Devices -> Network Settings

(Attached to: Bridged Adapter)

Note!: that by default Cable Connected (tick) is not selected so when imposing changes on Network – tick should be set)
After Specifying Attached to be Bridged Adapter to make CentOS linux refresh network settings run in gnome-terminal:

[root@centos ~]# dhclient eth0

However CentOS failed to grab itself DHCP IP address.
Thus I tried to assign manually IP addresses with ifconfig, hoping that at least this would work, e.g.:

on CentOS VM 1:

/sbin/ifconfig eth0 192.168.10.1 netmask 255.255.255.0

on CentOS VM 2:

/sbin/ifconfig eth1 192.168.10.2 netmask 255.255.255.0

To test whether there is connection between the 2 VM hosts tried ping-ing 192.168.10.2 (from 192.168.10.1) and tested with telnet if I can access remotely SSH (protocol), from CentOS VM2 1 to CentOS VM2 and vice versa, i.e.:

[root@centos ~]# telnet 192.168.10.2 22

 

Trying 192.168.10.2…
telnet: connect to address 192.168.10.2: No route to host

Then after checking other options and already knowing by using VBox NAT network option I had access to the internet, I tried to attach a standard local IP addresses to both Linux-es as Virtual interfaces (e.g eth0:1), .e.g:

On Linux VM 1:

/sbin/ifconfig eth0:0 192.168.10.1 netmask 255.255.255.0

On Linux VM 2:

/sbin/ifconfig eth1:0 192.168.10.2 netmask 255.255.255.0

Then to test again used telnet

[root@centos ~]# telnet 192.168.10.2 22

Then I found Virtualbox has a special Internal Networking support

to choose in Attached to drop down menu. According to Internal Networking Virtualbox instructions to put two Virtual Machine hosts inside an Internal network they should be both set in Internal network with identical name.
P. S. It is explicitly stated that using Internal Network will enable access between Guest Virtual Machines OS, but hosts will not have access to the Internet (which in my case doesn't really mattered as I needed the two Linux VMs just as a testbed)

virtualbox-create-internal-local-network-between-guest-host-Linux-Windows1

I tried this option but it doesn't work for me for some reason, after some time of research online on how to create local LAN network between 2 Virtual Machines luckily I decided to test all available Virtualbox Networking choices and noticed Host-only adapter.

Selecting Host-only Adapter and using terminal to re-fetch IP address over dhcp:

virtualbox-connect-in-local-lan-network-linux-and-windows-servers-hosts-only-adapter

On CentOS VM1

dhclient eht0

On CentOS VM2

dhclient eth1

assigned me two adjoining IPs – (192.168.56.101 and 192.168.56.102).

Connection between the 2 IPs 192.168.56.101 and 192.168.56.102 on TCP and UDP and ICMP protocol works, now all left is to install MySQL cluster on both nodes.

 

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Start Stop Restart Microsoft IIS Webserver from command line and GUI

Thursday, April 17th, 2014

start-stop-restart-microsoft-iis-howto-iis-server-logo
For a decomissioning project just recently I had the task to stop Microsoft IIS  on Windows Server system.
If you have been into security for a while you know well how many vulnerabilities Microsoft (Internet Information Server) Webserver used to be. Nowadays things with IIS are better but anyways it is better not to use it if possible …

Nomatter what the rason if you need to make IIS stop serving web pages here is how to do it via command line:

At Windows Command Prompt, type:

net stop WAS

If the command returns error message to stop it type:

net stop W3SVC

stop-microsoft-IIS-webservice
Just in case you have to start it again run:

net start W3SVC

start-restart-IIS-webserver-screenshot

For those who prefer to do it from GUI interface, launch services.msc command from Windows Run:

> services.msc

services-msc-stop-microsoft-iis-webserver

In list of services lookup for
IIS Admin Service and HTTP SSL
a) (Click over it with right mouse button -> Properties)
b) Set Startup type to Manual
c) Click Stop Button

You're done now IIS is stopped to make sure it is stopped you can run from cmd.exe:

telnet localhost 80

when not working you should get 'Could not open connection to the host. on port 80: Connection failed' like shown up in screenshot.

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Fix temporary DNS problems on Windows – ipconfig /flushdns

Monday, March 17th, 2014

fix temporary dns issues ipconfig /fush
My internet connection is coming router over a strange Belarusian ADSL modem "Промсвязь". This device serves as ADSL modem and a Wireless Router.
promsviaz_belarusian_adsl_and_wifi_modem

Periodically I'm experiencing issues with DNS, where there is internet but DNS resolving stops woring even though in ipconfig /all I can see DNS settings are proper:

C:\Users\hipo> ipconfig /all

...
Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) Centrino(R) Ultimate-N 6300 AGN
   Physical Address. . . . . . . . . : 3C-A9-F4-4C-E7-98
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::5d2f:97b8:9e1a:2b13%63(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.100.2(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : March 17, 2014 16:57:40 PM
   Lease Expires . . . . . . . . . . : March 18, 2014 16:57:40 PM
   Default Gateway . . . . . . . . . : 192.168.100.1
   DHCP Server . . . . . . . . . . . : 192.168.100.1
   DHCPv6 IAID . . . . . . . . . . . : 1094494708
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-19-CB-1A-5D-A4-5D-36-5A-EB-84

   DNS Servers . . . . . . . . . . . : 8.8.8.8
                                       192.168.100.1
                                       8.8.4.4

   NetBIOS over Tcpip. . . . . . . . : Enabled

 

The fix to situation is to Restart Promsvijazy and restart my Notebook. As this fix takes a lot of time I found another "work around". Make Windows Flush its DNS servers (forget old DNS servers and re-assign them again)

C:\Users\hipo> ipconfig /flushdns

Windows IP Configuration Successfully flushed the DNS Resolver Cache.


 

Other useful commands to make connection re-initiate completely are:

ipconfig /renew

Renews all Adapter settings (Lan, Wiki, PPP etc.) – re-assign IPs / re-initiate connections and

ipconfig /release

Releases any established connection

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How to configure VIVACOM 3g USB ( internet ) modem HUAWEI Mobile broadband E173 on Debian and Ubuntu GNU / Linux

Wednesday, July 4th, 2012

I've been given a HUAWEI Mobile Broadband E173 USB 3g model. The USB modem contains a flash USB Storage segment storing a little install program dedicated to make the modem work fine on Microsoft Windows XP / Vista / 7 and probably other M$ OSes. I'm a long time DebianGNU / Linux user and as a free software enthusiast I ofcourse wanted to be able to use Vivacom's 3G USB Modem on my Linux powered notebook.

Thanksfully as I've red on Vivacom's website the modem supports Linux OS 🙂

For those unaware in Bulgaria there are currently 3 major GSM network providers providing 3G internet this are;;;
 

  • VIVACOM – The ex Government ran national company BTC (Bulgarian Telecommunication Company)
  • M-Tel – The first GSM network provider that entered Bulgaria around year 1995
  • GLOBUL – The 3rd and last GSM mobile and net provider entered last and not so much used by Bulgarians today

Until today I had no experience in running any 3G modems on Linux, neither I had used the 3 networks 3G internet to determine which one is best, however I've been given for temporal use a VIVACOM 3G internet modem today so I proceeded to try installing it on my Debian host.

My Linux system is a bit strangely configured as I use wicd network connection manager -( wicd-gtk ) to manage wireless and LAN connections instead of the standard installed GNOME network manager – available through package ( network-manager-gnome ).

The reason I use wicd is not that it is so much better than GNOME network manger but rather for historical reasons because few years past I had impression it works better in connecting me to wireless networks. Another reason why I choosed wicd back then was the nice looking stats …

I tried plugging in the Vivacom USB 3G modem stick and checked in wicd to see if I can see a possibility to connect to the mobile opeartor 3G network but unfortunately nothing appeared.

Though the 3G adsl modem was unavailable straing in wicd, checking about it in the list of attached USB devices I could see it detected, e.g.:

noah:~# lsusb |grep -i huawei
Bus 001 Device 007: ID 12d1:1c05 Huawei Technologies Co., Ltd.

This was at least a good sign pointing me to the thoughts that the modem is probably gonna work.

I did a quick Google search to see if other people succeded running the device on a Linux host and came across a few blog posts in Bulgarian explaining a "success story" on Ubuntu Linux through using a tweakened shell script – sakis3g. For more on how the script works and script download check out Sakis3g

Here is a quote from sakis3g's website describing the script:
 

It automagically setups your USB or Bluetooth™ modem, and may even detect operator settings.
You should try it when anything else fails!

Sakis3g has different versions designed for for plenty of spacific hware architectures i.e. for (i386, amd64, armv4t, armv5t).
There is also a version of the script which by the way contains a combination of bash shell scripting instruction and some binary exec data.

To run sakis3g on my laptop I did:

1. Download sakis3g

My notebook architecture is 64 bit so I download and used the amd64 version of the script;;;

hipo@noah:~$ mkdir sakis3g
hipo@noah:~$ cd sakis3g
hipo@noah:~/sakis3g$ wget http://www.sakis3g.org/versions/latest/amd64/sakis3g.gz

I've made also a mirror of sakis3g i386, 64 bit and all architecture the mirrors just in case it disappears in future. The mirror versions of sakis3g are here:

a. sakis3g i386 b. sakis3g amd64 c. sakis3g all architectures source

2. Unarchive and make it executable

After downloading it as it is in gzip I had to do the usual de-gzipping and making the file executable;;;

hipo@noah:~/sakis3g$ /bin/gzip -d sakis3g.gz
hipo@noah:~/sakis3g$ chmod +x sakis3g

The script is then ready to run by either clicking twice on it or (as I prefer for debugging reasons to run it in terminal):

hipo@noah:~$ ./sakis3g

Something that I have wondered a bit was the dialog where I had to fill in some data of some variable APN abbreviation for – (Access Point Name)

The APN host for VIVACOM mobile internet is;;;
APN: internet.vivacom.bg

I've used the Windows configuration progrma to gather also the following data that I thought might be important for configuring the 3G adsl modem on the Linux host;;;

Auth: *99#
User: VIVACOM
pass: VIVACOM

Here are all the configuration screenshots I've taken from sakis3g and all the data that I filled in.
Next the following tiny window appeared on screen:

Sakis3g configure usb modem kdialog shot 1 VIVACOM USB Modem Sakis 3g Shot 2 sakis 3g usb modem vivacom connect screenshot 2 vivacom 3g modem linux sakis3g enter pin dialog shot 4 Sending pin screenshot 5 sakis3g APN Dialog sakis3g screenshot 6sakis3g Internet Linux VIVACOM screenshot 7sakis3g Debian GNU Linux VIVACOM 3g Internet screenshot 8sakis3g initializing modem screenshot 9sakis3g successful connect to VIVACOM mobile 3g usb adls modem shot 10

Well that's all folks, now sakis3g succesfully connected to the I_net via an (PPP) VPN connection tunnel here is data from ifconfig command showing the succesful 3G connection to VIVACOM;;;

noah:~# /sbin/ifconfig ppp0
ppp0 Link encap:Point-to-Point Protocol
inet addr:10.58.146.232 P-t-P:10.64.64.64 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:2066 errors:1 dropped:0 overruns:0 frame:0
TX packets:1609 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:2232058 (2.1 MiB) TX bytes:341693 (333.6 KiB)

The internet via the 3G connection is not blazing fast but good enough to check your mail or read some webpages. VIVACOM currently has different (traffic limited packages) for their 3G internet, I'm not sure which package exactly is the 3G USB stick modem but probably the "quick" internet connection that is now would slow down once the traffic limit is reached …
Hope this post helps someone to configure 3G internet on VIVACOM in Debian and Ubuntu Linux. Though I've tested sakis3g on Debian it should work with no hassles on any other GNU Linux distribution that has bash installed.

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Negative impact of Cell Phones (GSM) use on individual and society

Monday, June 25th, 2012

Negative impact of Cell Phones GSM on individual and society

We all live in an age, where cell-phone communication has become a standard part of our daily lives. As with everything new adopted in basic human life. GSM tool inclusion in our life had a severe impact on both individuals and in summary to whole society groups and nations.

The benefits out of having an instant “channel” for communication to anyone else in the world are indoubtfully numerous. However as present tosicety is learned to mostly thing in one direction, most people didn’t have a clear understanding on the negative impact of this little communicators on our mind body and soul.

1.; Negative impact of mobile phones on body level

Whenever we talk over the phone especially when picking up incoming calls or initiating out-going ones, the GSM device has to connect to the closest network cell “dial up” and wait for initialization of remote or local connection. The levels of radiation waves during the two mobiles connects up is higher. Therefore if one moves the phone near his ear listening for the status of call the amount of radiation that enters our brains is slightly higher. The extra-radiation whether mobiles are connecting is also few times more whether our phone is ringning, hence it is unhealthy to put the phone near our ear before we press the Answer Call button.

2.;; Negative effect of continuous mobile phones use on human brain

Knowing about the increased radiation on connection initialization thanksfully one can protect himself by simply not putting the mobile headset near ear on call initialization. Though this “problem” can be partially solved, next comes the health brain damage (tumours) which according to some researches are higher among people who do frequentlong phone call conversations. In long phone calls the brain is exposed for a longer time to the flowing waves making the peer to peer call possible. According to some medical researches, a long and frequent phone calls could be a reason not only for brain cancers but also other misfunctions or damages in normal brain cells functioning.

3.;;; The bad impact of Cell Phones on nervous system

Another health issue which the daily phone use and the constant exposure to mobile network cells radio frequency radiation affects generally our nervous system.

Unexpected phone calls early in morning or late at night are a cause for increased bodily stress and even the fear sometimes for an incoming phone call are a cause for many types of neurological disorders diagnosed by psychiatrists.
Even when we sleep at night the mobile phone periodically connects to the nearest mobile cell generating some almost undetectable “waves contamination”. This constant waves air flow caused by the mobile network cells positioned all around cities is not usual thing for our bodies. This also has some influence on our nervous system as the nervous sysm tends to be a bit more alert because of the waves constantly passing the body. The natural reaction of our bodies nerves is to try to balance itself. As nervous system of different people is not equal some people’s nervous system is more prone to having difficulties to balance the disbalance created by the increased number of mobile air waves.
The result of this to many people is in increased sleeplessnes and hardships to get asleep (according to research taken place in American Academy of Sleep Medicine.).

4.;;;; Lost of social and ethical behaviour in people

There is lately observed a huge shift from a face to face communication to peer to peer (p2p) on the phone. The cellphones breeds a culture of socially group detached people (the communication over phone is rarely a conference) but rather consists of communication between two persons (peer to peer). The p2p communication is not only a primary mean of communication of people exposed to heavy phone use. p2p Communication is a primary communication in Skype, Google Talk and mostly all modern available communication medias and softwares.

As more and more people spend nowdays more time on the mobile than in real communication, this makes them introverted and isolated and increases the inability to deal with real human f2f interaction. In other words continuous phone use re-trains us to communicate with others via the mobile. Besides that according to numerous researches about 40 to 50% of visual communication whether a phone call is used is lost (this also makes negotiation or expressing over phone harder and at least twice longer than in real communication).

The influence of the decreased social abilities cause of the phone use has also an impact on ethical behaviour of people too. The increased lost of communication abilities makes even daily real communication vague and lacking accepted social norms and ethical values. Next to that comes the huge problem of over-simplification of communication. As the line communication over the phone loose half of the communication as well as sometimes there are quality of voice over the network interferences. People are doing their best to simplify the communication adopting short command like like phrases and talking in a slang.

5.;;;;; Addiction to mobile phone use

The use of mobile phone often has a short beep sounds, whether you work on the keyboard receive a phone call or look for some mobile functionality staring at the screen. We’re wearing the mobile everywhere with us so often we do check the mobile screen quite un-consciously (by addiction). Checking the mobile screen to see what time is it has become almost an instinct and an automated learned behaviour.

The continous use of mobile phones makes many people mobile addicts. There are huge amount of people I’ve observed who speaks everyday for few hours (whether everytime they feel lonely they call someone in order not to feel lonely). The mobile phone addiction in youngsters is slighly higher than in adults. Probably the most mobile dependent addicts are kids who were given a mobile to use since there very early years.
Anyways there are tons of adults nowdays who cannot even think to be able to live without mobile and even cannot understand: how can anyone think that life could be possible without a cell phone. This kind of thinking is a direct trait showing an addiction and dependency on the phone such people have.

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Enabling talkd (Console Chat) between logged in users on FreeBSD and other BSDs

Sunday, June 10th, 2012

Talk between two useres on  FreeBSD 7.2 screenshot, console peer to peer interactive talk program UNIX, Linux, BSD

Those who are in familiar with older UNIXes, UNIX BSD derivatives and GNU Linux should certainly remember the times, when we hackers used to talk to each other using talk service.

Those who don't know what talk command is it is a simple console / ssh utility to talk to another logged in users.

Talk is very similar to write and mesg one liner messasing utilities available for *nixes, the difference is it is intendted to provide interactive chat between the two logged in users. People who came to know UNIX or free software in older times most likely don't know talk, however I still remember how precious this tool was for communication back in the day.

I believe still it can be useful so I dediced to install ot on one FreeBSD host.

In order to have the talk service running on BSD it is necessery to have /usr/libexec/ntalkd installed on the system this however is installed by default with standard BSD OS installs, so no need for any external ports install to run it.

talk doesn't have it's own init script to start is not written to run as it own service but in order to run it is is necessery to enable it via inetd

Enabling it is done by;;;

1 — Editting /etc/inetd.conf

Inside the conf the line::

#ntalk dgram udp wait tty:tty /usr/libexec/ntalkd ntalkd

should be uncommented e.g, become ;;;

ntalk dgram udp wait tty:tty /usr/libexec/ntalkd ntalkd

2 — Restart inetd

freebsd# /etc/rc.d/inetd restart
Stopping inetd.
Starting inetd.

talk is planned to be used for peer to peer conversations over SSH so in a way it is the GRANDFATHER 🙂 of IRC, ICQ and Skype;;;

Here is an example on how talk is used ,, Let's say there are three logged in users

pcfreak# w
12:39PM up 3 days, 16:25, 3 users, load averages: 1.12, 0.91, 0.71
USER TTY FROM LOGIN@ IDLE WHAT
testuser p0 192.168.0.7 10:50AM - bash
hipo p3 192.168.0.8 12:23PM - w
root p4 :ttyp2:S.0 12:24PM - vim /usr/local/www/dat

I'm logged in with my username hipo and I would like to talk to testuser ;;;;

pcfreak% tty
/dev/ttyp3

You see I'm logged in on /dev/ttyp3 (this is the specific naming on BSDs) on Linux equivalent is /dev/tty3So to talk the other user testuser;;;;;-

$ talk testuser ttyp0
[No connection yet]
[Waiting for your party to respond]

The testuser logged in via SSH will then get a message ||;

Message from Talk_Daemon@pcfreak at 12:44 on 2012/06/10 ...
talk: connection requested by hipo@localhost
talk: respond with: talk hipo@localhost

To enter a talk session then the logged in testuser has to type:

$ talk hipo@localhost

 

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‘host-name’ is blocked because of many connection errors; unblock with ‘mysqladmin flush-hosts’

Sunday, May 20th, 2012

mysql-logo-host-name-blocked-because-of-many-connection-errors
My home run machine MySQL server was suddenly down as I tried to check my blog and other sites today, the error I saw while trying to open, this blog as well as other hosted sites using the MySQL was:

Error establishing a database connection

The topology, where this error occured is simple, I have two hosts:

1. Apache version 2.0.64 compiled support externally PHP scripts interpretation via libphp – the host runs on (FreeBSD)

2. A Debian GNU / Linux squeeze running MySQL server version 5.1.61

The Apache host is assigned a local IP address 192.168.0.1 and the SQL server is running on a host with IP 192.168.0.2

To diagnose the error I've logged in to 192.168.0.2 and weirdly the mysql-server was appearing to run just fine:
 

debian:~# ps ax |grep -i mysql
31781 pts/0 S 0:00 /bin/sh /usr/bin/mysqld_safe
31940 pts/0 Sl 12:08 /usr/sbin/mysqld –basedir=/usr –datadir=/var/lib/mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –socket=/var/run/mysqld/mysqld.sock –port=3306
31941 pts/0 S 0:00 logger -t mysqld -p daemon.error
32292 pts/0 S+ 0:00 grep -i mysql

Moreover I could connect to the localhost SQL server with mysql -u root -p and it seemed to run fine. The error Error establishing a database connection meant that either something is messed up with the database or 192.168.0.2 Mysql port 3306 is not properly accessible.

My first guess was something is wrong due to some firewall rules, so I tried to connect from 192.168.0.1 to 192.168.0.2 with telnet:
 

freebsd# telnet 192.168.0.2 3306
Trying 192.168.0.2…
Connected to jericho.
Escape character is '^]'.
Host 'webserver' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'
Connection closed by foreign host.

Right after the telnet was initiated as I show in the above output the connection was immediately closed with the error:

Host 'webserver' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'Connection closed by foreign host.

In the error 'webserver' is my Apache machine set hostname. The error clearly states the problems with the 'webserver' apache host unable to connect to the SQL database are due to 'many connection errors' and a fix i suggested with mysqladmin flush-hosts

To temporary solve the error and restore my normal connectivity between the Apache and the SQL servers I logged I had to issue on the SQL host:

mysqladmin -u root -p flush-hostsEnter password:

Thogh this temporar fix restored accessibility to the databases and hence the websites errors were resolved, this doesn't guarantee that in the future I wouldn't end up in the same situation and therefore I looked for a permanent fix to the issues once and for all.

The permanent fix consists in changing the default value set for max_connect_error in /etc/mysql/my.cnf, which by default is not too high. Therefore to raise up the variable value, added in my.cnf in conf section [mysqld]:

debian:~# vim /etc/mysql/my.cnf
...
max_connect_errors=4294967295

and afterwards restarted MYSQL:

debian:~# /etc/init.d/mysql restart
Stopping MySQL database server: mysqld.
Starting MySQL database server: mysqld.
Checking for corrupt, not cleanly closed and upgrade needing tables..

To make sure the assigned max_connect_errors=4294967295 is never reached due to Apache to SQL connection errors, I've also added as a cronjob.

debian:~# crontab -u root -e
00 03 * * * mysqladmin flush-hosts

In the cron I have omitted the mysqladmin -u root -p (user/pass) input options because for convenience I have already stored the mysql root password in /root/.my.cnf

Here is how /root/.my.cnf looks like:

debian:~# cat /root/.my.cnf
[client]
user=root
password=a_secret_sql_password

Now hopefully, this would permanently solve SQL's 'failure to accept connections' due to too many connection errors for future.

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