Proximus BBOX 3 in bridge mode with prefix delegation on Linux

Using bridge mode allows you to get a public IP address on one computer (which can serve as a router) behind your modem. This allows you to know your public IP address without using a third-party service, and control more finely all your routing parameters inside your own Linux-based router (this tutorial) or a better router than the BBOX’s one.

We’ll call “the router” the device you want to use behind the modem for clarity.

The bridge mode of the Proximus BBOX 3 is quite interesting. You connect normally to your BBOX using DHCP and will get a locally routable address (i.e., but you can use PPP over Ethernet (PPPoE) to get a virtual interface inside your router. This virtual “ppp” interface will have a public IP address, and packets will flow IN and OUT the internet through that interface.

Proximus allows you to therefore maintain 2 PPP connections, one established by the BBOX (also used for the TV), and the other inside your router. It also means your home gets 2 IPv4 addresses.

I prefer that mode to the VOO one, where the external IP address is given by DHCP to only one host in the LAN, the first device to connect to the router using DHCP (dangerous and prone to configuration errors...). Same and independently for IPv6 using DHCPv6. While Proximus not only gives you an IPv6 address but also a /64 prefix via PPPoE to get a direct connection without using a crappy NAT to all your PCs. For IPv6, Proximus is much simpler than setting up an independent DHCPv6 client which gives back the v6 prefix to your LAN side. The second downside is that VOO must use ugly hacks to allow connection to the box as there is no "modem internal network" anymore. You can access your modem at the normally-illegal address as this is on the "public web" space from the router perspective. Moreover, it seems that the modem stops responding to DHCP requests from time to time, losing connectivity... VOO bridge mode is definitively not good... But this may be a temporary bug. I did not observe this anymore...

The bridge/WAN part

Edit /etc/network/interfaces to add the following lines , assuming that eth0 is the interface used to connect to your BBOX.

auto dsl-provider
 iface dsl-provider inet ppp
 pre-up /bin/ip link set eth0 up
 provider dsl-provider

Install pppoe with sudo apt-get install pppoe on ubuntu/debian or sudo yum install pppoe centos/fedora

Then create a file named /etc/ppp/peers/dsl-provider and add the following lines :

mtu 1492
plugin eth0
user "fc0123456@skynet"

Then edit the file /etc/ppp/chap-secrets and add the line :
"fc012345@skynet" * "password"

If you lost your skynet credentials (personally, I just never received them), you can change them online on MyProximus. You’ll have to reboot your modem so it receives automatically the new credentials.

And that’s all, you can reboot or do a sudo pon dsl-provider and you’ll have a new interface with a public IPv4 and a /64 IPv6.

The router/LAN part

To give connectivity in IPv4 for your hosts and use your Linux host as a router, you’ll have to do a NAT. But you can delegate your IPv6 range and give public IPv6 addresses to all your PCs using SLAAC! Remember to also install a firewall…

To do so, install radvd and add in /etc/radvd.conf (if br0 is the interface connected to your internal network) :

interface br0

 AdvSendAdvert on;
 prefix ::/64
   AdvOnLink on;
   AdvAutonomous on;
   AdvRouterAddr on;
 RDNSS 2001:4860:4860::8888 2001:4860:4860::8844
   # AdvRDNSSLifetime 3600;

Then do a sudo radvd restart and that’s it.

The RDNSS line gives the address of Google’s public DNS to your host. We could use Proximus’ one, but I don’t have the address on hand.

Do not hesitate to contact me!

14 Replies to “Proximus BBOX 3 in bridge mode with prefix delegation on Linux”

  1. FYI, the management URL of a Voo modem is reachable through IP even if the router is configured in Bridge mode.

    1. Thanks ! I saw that a few days after posting this, my comment was awaiting my own approval… It stills lack a little documentation somewhere… The modem itself says that it won’t be reachable anymore. I’ll test the VOO bridge mode a little more and update my post, it also seems more stable now. Maybe it was just a temporary problem… I’m currently fighting to do a dual-home with a Proximus fon hotspot now.

  2. Hello,
    Any update on how to be able to connect the Belgacom TV Decoders onto your own network?

    Does it still setup a “IPoE” Connection to Belgacom for the TV’s?
    Or is it possible to just Bridge the VLAN 30 (TV Vlan) to your own network?

    (Belgacom screenshot:

    Is it possible to create a virtual interface on the Linux host that listens to VLAN 30 and bridges this with the new network (After PPoE)


  3. A little update : It seems that Voo is now also giving an IPv6 prefix in bridge mode 😉 If they stop charging up to 50€ per month when you go over your quota without telling you anything I may finally prefer them…

  4. Thanks for this. I was pretty confused how bridging would work when you don’t change any configuration on the BBox3. You cleared that up by explaining that they allow two simultaneous PPPoE connections with the same credentials (although it seems the bridge transmits over the BBox3 LAN, adding latency).

    Got it up and working in DD-WRT by using their “PPPoE Dual” WAN connection type, and setting a static IP/gateway on my BBox3 LAN.

  5. Tom,

    Is a delegated prefix not needed for this?
    I’m wondering how the internal network will get the ppoe connection prefix?


    1. Hi!

      That’s the magic, PPPoE use discovery. So your router will find run PPP discovery and find your modem can provide it. Then it will tunnel PPP packets.


  6. Fedora distro’s don’t have a /etc/network/interfaces file. Any idea what the fedora alternative would be?

    1. It’s in /etc/sysconfig/network-interfaces, see

      But it won’t be exactly the same format… You’ll have to try-and-error I guess

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