Install OpenWrt on NB6 / NB6V (SFR)

Hi Guys,
I am owner of an old SFR NB6V router and i'd like to migrate it to OpenWrt. I have understank it will disable *DSL availability, but I have now another ISP and like to test OpenWrt, to play with, it will come in addition.
I assume firmware is the same for NB6 and NB6V. I have search on forum but can't find any help
I have try to install throught TFTP, by putting OpenWRT firmware for NB6 device on it.
I have try to boot NB6V in "intall mode" by hold on "SFR buttun" until red light, was assuming when doing this, device automatically download new firmware from TFTP repository (I have configure DHCP server to boot with TFTP) but seems I am on the wrong way.
If someone can give me some tricks on how to install OpenWRT on this device, it will be greatly appreciated.
Thank you


copied from :

Configuration de dnsmasq

On considère ici que dnsmasq est déjà l'unique serveur DHCP actif sur le réseau et donc que le reste de la configuration est fonctionnelle.

Editer le fichier de configuration /etc/dnsmaq.conf et ajouter les lignes suivantes

#activation du serveur TFTP enable-tftp #Déclaration du répertoire cible tftp-root=/tftpboot #Déclaration du fichier à charger dhcp-boot=OPB6-MAIN-R3.1.4

Le répertoire cible devra être accessible en lecture par tous

sudo chown nobody:nogroup /tftpboot


Connecter la box à flasher sur le réseau au moyen d'un câble ethernet.

Eteindre la box avec l'interrupteur arrrière.

Maintenir appuyer le bouton service pendant que vous rallumez la box (quelques secondes de maintien)

Priez Saint EDF qu'il n'y ai pas de coupure secteur.

Au bout de 8 secondes, les voyants doivent passer au rouge "tournant" et une activité de transfert est visible sur la led du port ethernet.

La procédure de flashage prend environ 2 minutes.

Quand vous récupérez l'accès à la page d'administration, via votre navigateur préféré, c'est terminé.

Hi Madagaga,
Thank you for reply.
My issue is not about uploading Firmware, but seems NB6V does not install it. My TFTP server in working and I can see in logs than NB6V upload it, the issue seems on the firmware itself.
I have try to load 4 firmware (succesfully loaded but not applied) :

  1. The 'official' NB6 from openWrt website (
  2. The official one with this script applied (

2 parameters : first = input second = output

cat /dev/zero | tr '\000' '\377' | dd bs=64k of=$2 count=128 seek=0
dd bs=64k of=$2 if=$1 seek=1
dd if=/dev/zero bs=64k of=$2 count=1 seek=127
to transform file on a recognized "format"
3) Compiling a NB6V firmware on my own following
4) The compiled firmware with the script applied
Without any success for the 4 firmwares.
If anyone have an idea.
Thank you

Ok, I didn't understand that.
I have flashed mine but it's a nb6. I think nb6v has another soc as nb6 is adsl only and nb6v is adsl/vdsl .

Hi, tell me, is it possible to upgrade the sfr nb6v-fxc-r0 router with openwrt firmware?

In theory, yes, but have not find yet a way to do it via TFTP

1 Like

Ok, just find a solution, please write in the subject please. And another question, I have firmware 3.3.9. Where can I download more new firmware, I can not find.
Sorry for my English, I'm from Ukraine, and I use google translator

@Roudoudou this should help