Set Wired Network Connection On Ubuntu

1. Click on network option on top right.

2. Then navigate to “VPN Connections” and click “Configure VPN”.

3. Click “Add” on “Wired” tap.

4. Now enter a name to your new connection.

5. And select “IPv4 Settings” option and select “Manual” on “Method” option.

6. Now click “Add”, and enter following values on specific fields.

7. Address: <Your system IP> Example: 192.164.1.7

                   Note: You can get it via entering “ipconfig” in ubuntu terminal.

  Netmask: 255.255.255.0

  Gateway: <Your router IP / Gateway> Example: 192.164.1.1

                   Note: You can get it via entering “route -n” in ubuntu terminal.

  DNS servers: 8.8.8.8

  Search domains: 8.8.4.4

8. Check “Available to all users” check box, if you wish. So that anyone on that system can use this config.

9. Now click “Apply”.

File and Directory Permissions in UNIX / Linux

Source: UNIX / Linux: Beginners Guide to File and Directory Permissions

Unix file and directory permission is in the form of a 3×3 structure. i.e Three permissions (read, write and execute) available for three types of users (owner, groups and others).


Three file permissions:

• read: permitted to read the contents of file.
• write: permitted to write to the file.
• execute: permitted to execute the file as a program/script.

Three directory permissions:

• read: permitted to read the contents of directory (view files and sub-directories in that directory ).
• write: permitted to write in to the directory. ( create files and sub-directories in that directory )
• execute: permitted to enter into that directory.

Numeric values for the read, write and execute permissions:

• read 4
• write 2
• execute 1

To have combination of permissions, add required numbers. For example, for read and write permission, it is 4+2 = 6.

Change File and Directory Permissions Using Chmod Command
You can use either the octal representation or symbolic representation to change the permission of a file or directory.

Octal representation for permissions:

• First number is for user
• Second number is for group
• Third number is for others

For example, give read, write ( 4+2 = 6 ) to user and read ( 4 ) to group and others.

$ chmod 644 filename

For example, give read, execute ( 4 + 1 = 5 ) to user and read (4 ) to group, and nothing ( 0 ) to others.

$ chmod 540 filename

For example, give read, write ( 4 + 2 = 6 ) to user and nothing ( 0 ) to group, and read ( 4 ) to others.

$ chmod 604 filename