Debian 13 Trixie software repository information

Here are the steps to add the main repository address to Debian 13 (Trixie).

Add to sources.list

Open the sources.list using your favourite text editor (e.g. Mousepad),

sudo mousepad /etc/apt/sources.list
Copy and paste the following lines into the file,
deb http://deb.debian.org/debian/ trixie main non-free-firmware
deb-src http://deb.debian.org/debian/ trixie main non-free-firmware
deb http://security.debian.org/debian-security trixie-security main non-free-firmware
deb-src http://security.debian.org/debian-security trixie-security main non-free-firmware
# trixie-updates, to get updates before a point release is made;
# see https://www.debian.org/doc/manuals/debian-reference/ch02.en.html#_updates_and_backports
deb http://deb.debian.org/debian/ trixie-updates main non-free-firmware
deb-src http://deb.debian.org/debian/ trixie-updates main non-free-firmware

Save and close the file. Update the repository list and upgrade the packages by applying the following commands;
sudo apt update
sudo apt upgrade

Debian 10 (Buster) Indian repository

Debian Indian repository can speed up the download speed while upgrade and installation of new packages. Indian users get the advantage of local Debian repository. Here is the Indian repository of Debian 10 (Buster).

Add to sources.list

Open the sources.list using your favourite text editor,

su
mousepad /etc/apt/sources.list
Delete or comment out the existing repository details in the file. Copy and paste the following content into the file.
deb http://debianmirror.nkn.in/debian/ buster main
deb-src http://debianmirror.nkn.in/debian/ buster main
deb http://security.debian.org/debian-security buster/updates main
deb-src http://security.debian.org/debian-security buster/updates main
# buster-updates, previously known as 'volatile'
deb http://debianmirror.nkn.in/debian/ buster-updates main
deb-src http://debianmirror.nkn.in/debian/ buster-updates main
Update the repository list and upgrade the packages
apt update
apt upgrade

Debian 9 (Stretch) Indian repository

Debian Indian repository can speed up the download speed while upgrade and installation of new packages. Indian users get the advantage of local Debian repository. Here is the Indian repository of Debian 9 (Stretch).

Add to sources.list

Open the sources.list using your favourite text editor,

su
leafpad /etc/apt/sources.list

Delete or comment out the existing repository details in the file. Copy and paste the following content into the file.

deb http://debianmirror.nkn.in/debian/ stretch main
deb-src http://debianmirror.nkn.in/debian/ stretch main

deb http://security.debian.org/debian-security stretch/updates main
deb-src http://security.debian.org/debian-security stretch/updates main

deb http://debianmirror.nkn.in/debian/ stretch-updates main
deb-src http://debianmirror.nkn.in/debian/ stretch-updates main

Save and close the file.

Apply the following commands to update the repository information.

apt update
apt upgrade

How to add Debian software repository

Software repository does not add when we install Debian Linux from CD/DVD without Internet connection. You can't update the Debian Linux without software repository. But you can add software repository later. Find a repository near your area. Download from remote server take long time to download updates.

You can find Debian software repository near your area by visiting Debian Source List Generator. 

In my experience, repositories from India is slow and so I make use Debian repositories from Japan. 

Add repository address to Debian

Open Applications > Accessories > Terminal 

Open sources file and add repository address.

su

leafpad /etc/apt/sources.list

Copy paste the lines to the file. Here is the repository from Japan,

deb http://ftp.jp.debian.org/debian/ wheezy main
deb-src http://ftp.jp.debian.org/debian/ wheezy main

deb http://security.debian.org/ wheezy/updates main
deb-src http://security.debian.org/ wheezy/updates main

# wheezy-updates, previously known as 'volatile'
deb http://ftp.jp.debian.org/debian/ wheezy-updates main
deb-src http://ftp.jp.debian.org/debian/ wheezy-updates main

Save and close the file. Update the sources list.

apt-get update