When we try to update kali, all the necessary files are fetching from the default repository of Kail Linux https://http.kali.org/
You can check that in /etc/apt/source.list using command
A default repository redirects you to the nearest server, which is available to your location, Because of the large number of ongoing connections to the nearest server, it overloads the capacity than required. Due to that, downloading is slow, and even if you have a good speed.
To solve this issue will use a mirror, there are so many mirrors out there, check https://http.kali.org/README.mirrorlist
But in this case, I will use (OCF) The Open Computing Facility at the University of California, Berkeley hosts mirrors of free and open-source software project archives. These mirrors are available via HTTP: http://mirrors.ocf.berkeley.edu/
To do this we will make changes to the source. list file before that makes sure to create a backup of the source.list. using the following command
# cp /etc/apt/sources.list /etc/apt/sources.listbak
Next open sources.list and erase everything
# nano /etc/apt/sources.list
Next copy the following and paste it into sources.list
deb https://mirrors.ocf.berkeley.edu/kali/ kali-rolling main contrib non->
# For source package access, uncomment the following line
# deb-src https://mirrors.ocf.berkeley.edu/kali/ kali-rolling main contrib>
Now save this file and run the update process.
# apt clean # apt update && apt upgrade -y
I hope the Issue was solved.