uname

Get all host information in a single string 

uname -a
Linux my-hostname.com 3.13.0-68-generic #111-Ubuntu SMP Fri Nov 6 18:17:06 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Get kernel name

uname -s
Linux

Get network node name

uname -n
my-hostname.com

Get kernel version

uname -r
3.19.0-33-generic

Get  16/32/64 bit hardware platform

uname -i
x86_64

Canon MF-4410

Go to Canon web site and find in supported list your model i-SENSYS MF4410. In drop down menu choose Linux 32 or 64 bit system. To check your platform use uname  -i command. 

Download Linux_UFRII_PrinterDriver file and extract to  folder

tar -xf Linux_UFRII_PrinterDriver_V310_uk_EN.tar.gz

Turn off your printer and install packages from 32 or /64-bit_Driver/Debian wirh dpkg command.   

dpkg -i cndrvcups-common_3.40-1_amd64.deb cndrvcups-ufr2-uk_3.10-1_amd64.deb

Turn on printer and wait while computer finds your printer itself

If you get a “device is busy”message while scaning, go to your Canon MFU device, press Copy button and choose “remote scaner” item and try again. 

 

 

fail2ban

Configuration file /etc/fail2ban/jail.conf has predifined sections for most used services such as: ssh, mysql, asterisk, apache, pure-ftpd etc.

In the top of the file there is a default section for default items values.

[DEFAULT]
# exclude IP adresses from ban list
ignoreip = 127.0.0.1/8 192.168.0.0/16

# ban time in seconds
bantime = 600

# log fie range records for scanning in seconds
findtime = 600

# maximum retries before ban
maxretry = 5

# comma delimited ports or iptables-allports 
banaction = iptables-multiport

# tcp or udp
protocol = tcp

Each section has name and its items.  Lets look for ssh service section.

[ssh]
# true or false
enabled = true

# port number or name described in /etc/services
port = ssh

# filter name is a file name in a directory /etc/fail2ban/filter.d 
filter = sshd

# file to parse
logpath = /var/log/auth.log

# retries before ban
maxretry = 6

# or use your own action
# action = iptables-multiport[name="sshd", port="22", protocol="tcp"]

Files with ban rules located in directory /etc/fail2ban/filter.d and have *.conf extension. Rules in configuration file are regular expression strings delimited with CR (new line). 

failregex = ^%(__prefix_line)s(?:error: PAM: )?[aA]uthentication (?:failure|error) for .* from <HOST>( via \S+)?\s*$
 ^%(__prefix_line)s(?:error: PAM: )?User not known to the underlying authentication module for .* from <HOST>\s*$
......

To check rules in log file use fail2ban-regex command. The result is count of rules match. For more verbose use option -v.

fail2ban-regex /var/log/auth.log /etc/fail2ban/filter.d/sshd.conf

Check iptables for your rules

iptables -S | grep fail2ban

If everething is ok wait for a while (findtime), and see ban statistic via command

fail2ban-client status ssh

All fail2ban activity stored in fail2ban.log file. Default verbose level is 3 and can be set in range 1-4. More detailed is 4 – DEBUG

fail2ban-client set loglevel 4

 

Permanent ban 

In current version (0.8.11-1) there is no increasing exponential time ban. It would be good to ban IP for the first try for a 1 hour, second try for 1 day, third try for 1 week etc. There is a trick to write new rule controlling fail2ban.log file itself.

Create file /etc/fail2ban/filter.d/fail2ban.conf

[Definition]
# Count all bans in the logfile
failregex = fail2ban.actions: WARNING \[(.*)\] Ban <HOST>

# Ignore our own bans, to keep our counts exact.
ignoreregex = fail2ban.actions: WARNING \[fail2ban\] Ban <HOST>

Add to file /etc/fail2ban/jail.conf following section

[fail2ban]
enabled = true
filter = fail2ban
logpath = /var/log/fail2ban.log
maxRetry = 5
findtime = 36000
bantime = 360000
action = iptables-allports[name=fail2ban, protocol="all"]

It means when 5 bans occuers within last 10 hours host will be blocked for a 100 hours. 

mount.davfs

To allow other users to mount davfs file system you need reconfigure davfs2. Run dpkg-reconfigure and answer YES.

dpkg-reconfigure davfs2

Add users to davfs2 group. Replace UserXX with proper value. Each user will be able to moun media into own home directory

usermod -aG davfs2 UserXX

To make permanent mount point in /mnt/MyDavFS directory, first create it with mkdir command

mkdir -p /mnt/MyDavFS

Add mount point,user name, password to secret file /etc/davfs2/secrets

/mnt/MyDavFS UserXX PasswXX

Add following line to file /etc/fstab

http://YourHostName/ScriptName /mnt/MyDavFS   davfs   user,auto,rw  0 0

dmesg

Show all buffer

dmesg

Show CPU frequency

dmesg | egrep -i --color 'MHz'

Show memory info

dmesg | grep -i available |egrep -i --color 'Memory'

Show video card information

dmesg | egrep -i --color 'vga|agp|3d|2d'

Show network card information

dmesg | egrep -i --color 'eth|wlan'

Show webcam information

dmesg | egrep -i --color 'UVC|WebCam|Video'

Clear the ring buffer

dmesg --clear