How to intall Openwrt on FritzBox 4020

Hey geys,

I am new here and want to flash the Router FritzBox-4020!

I visit the
and downloade the file.....
after reserach i found a for 4020

and here i am stock:

# ./ openwrt-18.06.2-ar71xx-generic-fritz4020-squashfs-sysupgrade.bin

Flashing image openwrt-18.06.2-ar71xx-generic-fritz4020-squashfs-sysupgrade.bin to FritzBox at

This script will flash a given image to mtd1 of a FritzBox device.

This process will take some time!

About 2 Minutes for a 1750E.
About 2 Minutes for a 4020.
About 5 minutes for a 4040.

If you want a status bar: Attach a serial to the device and look there.

In case this process has not terminated after 10 minutes:
 - Terminate this process first!
 - Powercycle FritzBox
 - Retry

(Note: Make sure that you connected the router on the yellow LAN ports and not the blue WAN).

./ 48: ./ ftp: not found
# PING ( 56(84) bytes of data.

--- ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.450/0.450/0.450/0.000 ms

i used Linux becaus though will by eayser but yes...
hopfully someone can help me!
if it eayser for ther system , let me know.

You need to install a simple (cli-) ftp client on your linux system, on Debian based systems one option would be the ftp-ssl package (given that it couldn't even begin with the flashing in the absence of a suitable ftp client, it's safe to terminate the script).


thanks, a lot slh.

i got it done wit the cilent

If anyone might find themselves in a similar situation: There is a Python implementation which has no dependencies beside the core python3 (It even runs on Windows) I've written a while back: was essentially a copy of the flash-script for the 4040 with adapted messages for other devices.

Documentation is available at

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