Using a Billion 7800N with Sky Broadband Unlimited and MER


The Billion 7800N is a very highly rated ADSL2+ Router and for good reason. Although slightly more expensive than a number of home use routers the Billion 7800N comes packed with many enterprise quality features that make it stand out.

It’s got N wireless with 3 removeable antenna, it supports a dual WAN connectivity that allow the use of both PPOE and PPOA connections and is incredibly stable. Sky Broadband insist that you use their routers and rightly or wrongly, this is not for debate here. It’s part of their terms and conditions and if you don’t like it, change provider. What I wanted to share with you is how I’ve managed to integrate my Billion 7800N into my home network, take advantage of it’s features and all without breaking Sky Broadband’s terms and conditions.

In summary then – I use the Sky Broadband provided Sagemcom F@ST 2504N as a front end ADSL modem that passes all the traffic onto the Billion 7800N at the heart of my home network.

Before we get into the configuration, I wanted to share a few words on the ‘workarounds’ several sources are suggesting to get around MER.

In simple terms, MER is a form of authentication that uses the MAC address of the Router to allow connection to the Internet Service Provider.  Not all Sky Broadband customers are currently running on MER – but the intention seems to be to roll this out nation wide.

MER in itself is not an issue to work with – as long as your router supports MAC Address Spoofing, you’re able to make it appear to be another device (ie the one you’re supposed to be using).  However, it would appear that Sky Broadband are using an additional step in ensuring that it’s customers only use the provided modem – which is to use a custom DHCP configuration that will only lease IP addresses to it’s own Routers.  Unfortunately, this means that if you don’t play by the rules and you try some of the afore mentioned advice which is to start connecting your Sky router to get the IP address and then set it statically you’re just asking for trouble.  DHCP allocates it’s addresses by means of a Pool.  When an address is leased properly, the Pool is updated to ensure that the same address cannot be taken again.

The suggestions are that you just copy your old IP address and then use it until it stops working – then – reconnect your old router again, get a new lease and retry.  In one way, this will work.  You will get a connection and you can happily use your shiny new Router.  However what they probably don’t understand is that this breaks one of the main principles of DHCP and you’re basically taking assigned addresses from the Pool and trying to use them as static addresses.  This will lead to IP address conflicts where two addresses are the same and both devices (or customers) will become unable to use the Internet.

My advice?  As stated before – if you’re not happy with Sky Broadband’s T’s and C’s, change provider otherwise stick to using the Router that they provide and if you want to make use of another router as well, use it downstream.

Now, onto a method of using your Sky Router as just an ADSL modem and allowing your Billion 7800N to do everything else such as Wireless, DHCP, DNS and Firewalling.

The first thing you’ll need to do is plan your IP address structure.  I’m going to use sample addressing here – which should work for most – but if they don’t, feel free to post a comment and ask for help.

We’re using the following IP addresses:

WAN address of Sagemcom F@ST 2504N – Dynamically assigned by Sky
LAN address of Sagemcom F@ST 2504N – /
WAN address of Billion 7800N –
LAN address of Billion 7800N –

From a physical connection point of view, we do the following:

  1. Connect the Sagemcom F@ST 2504N to the ADSL connection
  2. Run a CAT5 patch cable between Port1 on the Sagemcom F@ST 2504N to the EWAN port on the Billion 7800N.  Ideally you should use a crossover cable, but a normal cable seems to work due to one or both of the routers supporting auto sensing.
  3. Connect all other devices either wired or wireless into the Billion 7800N

So first, the settings for the Sagemcom F@ST 2504N:

Wireless Settings (We disable all Wifi so that the Billion can handle)

sagemcom 2504N wifi
Disable Wifi on Sagemcom 2504N

WAN Settings (We setup a default DMZ address and point it to the WAN address of the Billion 7800N)

sagemcom 2504N wan
Setup DMZ on the Sagemcom 2504N

UPNP Settings (As we’re using a DMZ address which pushes all traffic to the Billion 7800N, we disable UPNP on the Sagemcom F@ST 2504N)

sagemcom 2504N upnp
Disable UPNP on Sagemcom 2504N

We now need to make changes to the Billion 7800N:

LAN > Ethernet (We start by ensuring the LAN settings are correct)

billion 7800n lan
Billion 7800n LAN settings

WAN > WAN Profile (We need to create a new Profile that’s based on the EWAN port.  As you can see, we use the Sagemcom F@ST 2504N LAN IP address for the Gateway and DNS server.)

billion 7800n wan
Billion 7800n WAN Profile using EWAN

WAN > Interface (We then need to select EWAN from the Main Port dropdown)

billion 7800n wan interface
Billion 7800n Select EWAN

You then configure the rest of the Billion 7800N how you would normally – if you need any help with Wifi, DHCP or general settings, let me know in the comments.

Once this is complete and both devices have been restarted you will find that you can now use the exciting features of the Billion 7800N for your Home Network whilst retaining the Sky Broadband provided Sagemcom F@ST 2504N and remaining within the terms and conditions.

Essentially the Sky Broadband Sagemcom F@ST 2504N is used as a simple ADSL modem that passes all traffic to the Billion 7800N.  The Billion 7800N is for all intent and purpose your Router but instead of connecting direct to the Internet – it passes all outbound traffic through the Sky Router.

In my opinion – everyone wins.

I hope you have enjoyed this article and please feel free to post any questions or suggestions of your own in the comments.


  1. awesome article Biggeek – never thought of doing that.

    how would I use different dns servers like google dns or opendns with a setup like this?

  2. Hey Stu2k.

    I personally use OpenDNS for my DNS.

    When configuring the Billion 7800N On the WAN Interface page you can enter whichever Primary and Secondary DNS servers you want your DHCP clients to use.

  3. Hey Ryan. Yes, by setting a default DMZ address you are bypassing the firewall functionality of the Sky Router and passing all packets to the Billion which will use it’s own firewall.

  4. I won’t ctually be using a Billion, I’m going to try this with my Netgear DGND3700 router.

    Thanks for the guide 🙂

  5. Hi BigGeek,

    First of all, thanks very much for the post. It seems to be a great work around, but I cannot get it to work. If you can offer any advice, I’d really appreciate it!

    First of all, my Sagem router runs its LAN IP address starting with No big issue, I figured I would just swap your suggested IP addresses around from what you have stated above. I then went on to follow all of the steps to reconfigure the Sagem router as per the instructions you have listed. This went without issue until step 2 (DMZ address). To access the 7800N’s OS when physically connected to the Sagem, I have to use as the IP address. Your screen shot shows, but you have earlier suggested the 7800N WAN address (before using the screenshot instructions) should be If I’m working with a LAN IP range starting on the Sagem – Should the DMZ be set to or something else?
    I tried and completed the rest of the changes for the Sagem router as instructed.

    When I got to the 7800N settings, (step 4 checking the 7800N LAN settings) the IP address was already showing as – I changed this to and clicked apply which prompted a restart. After the restart, I got a message to tell me that could not be accessed. I tried to access 7800N’s OS using a number of other guessed IP addresses but got nowhere. The only thing I could do was a factory reset on the 7800N to start over again.

    After the Factory Reset, I started again, but this time left the LAN address (step 4) as and moved on to step 5. I configured the WAN profile as you have in your screenshot, but instead used as the IP address and as the primary DNS and gateway IP I then restarted the router as prompted.

    Finally I changed the WAN interface to EWAN and clicked apply which restarted the router again. To be sure, I then rebooted both devices but when both had come back up, I couldn’t access the internet nor could I reach the OS of either router (using or I even rebooted my machine (MAC) and cleared the history in google chrome, but still could not get access to anything.

    In the end, I had to factory reset the 7800N before I unplugged it and then undid all my changes to the sagem router.

    Any advice? Also, why do I have an IP range starting on the Sagem when almost everyone else is

  6. Hi Mark C,

    Glad you found the article useful.

    Before deciding on which IP addresses you are going to use, you need to understand exactly how your network will look once these changes are made.

    Internet (IP Address provided by Sky, so something like This is on the OUTSIDE of your Sagem, it’s the IP address the world see’s you as.)
    Sagem LAN Address ( – Which I believe is the default)
    Billion WAN Address ( – Has to be in the same range as the Sagem, and it is the address the Sagem passes everything onto)
    Billion LAN Address ( – This is the address all of your devices will use as their gateway)
    I hope this makes a little more sense, if not shout back and I’ll help.

  7. Oh and in terms of your Billion LAN address being unreachable, you just need to make sure that any changes you make to either device don’t leave you stranded and unable to connect to them using your pc or laptop.

    If you end up stranded, just statically set your PC or Laptop with an IP in the same range and plug in directly.

    For example:

    Router IP =
    PC Address =


    Router IP =
    PC Address =

    When you look at the subnet, just see the 255’s as saying ‘these bits are all the same’. This then seperates out your network ID (the bit that the 255’s match) and your host ID, the last number.

  8. Thanks BigGeek,

    Unfortunately I won’t get a chance to attempt any changes for a few days, but I’ll let you know how I get on. The only thing that still puzzles me is why my Sagem router’s default IP address range is this is not something that I ever set up?

  9. Alrighty – will look forward to your update.

    I guess the default IP’s may vary depending on Sky’s configuration at the time.

    If your Sky Router is I’d suggest trying the following:

    Sky Router LAN –
    Mask –
    DMZ Address –

    Billion WAN Setup –
    Mask –
    Default Gateway –
    DNS Server –

    Billion WAN Setup –
    Mask –

    DHCP Should do the rest, but if for some reason it doesn’t – connect your PC or Laptop direct into the Billion and use the following manual configuration:


    From that PC you should then be able to reach the Internet….

    Good luck!

  10. Hi there.

    So, after much cursing my Sagem F@st sky router i went and bought the Billion knowing this guide was around.. So tonight i’ve done exactly what your guide says, but currently can’t get the Billion wifi signal to work. I can still use the sagem network to surf, but the new network doesn’t work. (however i can log onto the unit at

    ANy troubleshooting advice??

  11. Hey David,

    Sorry to hear you’re having problems.

    Wifi troubleshooting is an art in itself, but I’m sure that we can work out what’s going on here.

    Couple of simple things first – have you disabled the Wifi on the Sky Router? If not, you might be connecting to that first which will give you a connection in between the routers instead of from behind the Billion.

    Also, how have you configured Wifi on the Billion? Which options have you selected? It could be that you have chosen a Wifi mode that isn’t supported by your client.

  12. hiya…

    So, yes i’ve disabled the sky wifi. I’m working on a Macbook Pro and can see the Billion network in my wifi list which i can connect to and allows me to look at the Billion settings pages (
    My billion settings aren’t anything out of the ordinary.

    WLAN Service – enabled
    EESID – Rodg3r51
    ESSID Hide – Disabled
    Regulation Domain – Europe
    Channel ID – Channel 11
    Security Mode – WPA2
    Radius / 802.1x – Not enabled
    WPA Shared key – xxxxxxxxx
    Group Key renewal – 3600

    Main Port – EWAN
    Protocol – Fixed IP Address
    IP Address –
    Netmask –
    Gateway –
    Option DNS – disable
    Primary DNS/Secondary DNS – /
    vlan mux – disable
    (nothing else ticked)

    And on my sky box i set the DMZ as, and turned off the UPnP.

    1. Don’t worry, it’s working now! Don’t know what happened….. Anyhow, thanks!!

      Oh, i’m not really that techy but you may be able to answer me this.

      I have various devices using my home network (2 x iphones, ipad, 2 x Macbook Pros, Mac Mini Server, B&W Airplay Speaker, and Apple TV – Yes yes, Apple freak!!) and transfering files from my laptops to my server was taking forever, and streaming music to my speaker kept dropping out. The reason for buying the new router was to hopefully help the problems of network strength and transfer rate. Will this new router help?? How can i configure the Billion to be optimum for my home network???

      1. That’s great news 🙂

        In terms of performance, there are many things that can lead to poor performance.

        The single biggest tip when troubleshooting wifi is try all three ‘main’ channels and test before deciding which to go with.

        The main channels are 1, 6 and 11. You might find that someone else is using your channel and by swapping to one that isn’t occupied you could well see an immediate improvement.

        1. hi again…

          so ive found an issue. My server wont connect to the internet. All my other devices work fine, just the server. I did see something in the connection assistance that said something about DCHP….

          Any idea what that may be??

          1. Hey,

            That sounds to me like the Default Gateway or DNS addresses are set wrong on the server. Make sure that both are pointing to the IP address of your Billion router.

  13. Hi Biggeek
    Great article & i set up this morning and all is running smashing, thank you.
    Theres just 1 think im not sure about. DNS. The sky router is (obviously) set to skys dns settings(as they cant be altered that im aware of.
    Now in the Billion router settings i have Obtain DNS, automatic, unticked. and have in the primary (which is the same as in the Gateway) and nothing in the secondary.
    Now to my question, i like to use google dns, so if i put them in the primary & secondary do they override the sky routers setting (sky’s dns)?
    Hope that makes sense.
    Best Regards, Will

    1. Sorry I didn’t see this sooner Will – I’m guessing you’ve found your answer but just in case…

      Although the Sky Router is still using Sky’s DNS – this will only affect anything that is using the Sky Router as it’s DNS server – anything that’s getting DHCP from the Billion will use whatever you set in the DHCP config.

      Hope this helps.

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  15. Hi I hope this isn’t one of those senior moments I’m having, but I’ve been reading that a firmware update is needed on the Billion for it to work on the Sky line. Will this work first of all without getting the firmware update or do I need to update it on another ADSL line say a neighbours?

  16. Hey Frosty.

    This article is about using the Billion Router in conjuntion with your Sky Router – not instead of it.

    If you are going to use the Billion instead, I’d recommend either downloading the firmware using your normal Sky Router first, or as you say – use someone elses connection.

  17. Hi if you use this set up will you still be able to tweak the SNR settings on the Billion Router or not? You cannot do this on the Sky Router but I would like to be able to do this.

    1. Hey Sean,

      Unfortunately the SNR setting only works when the Billion is directly connected to the ADSL line so in this setup it won’t work.

  18. Although messy, there is nothing wrong with having multiple hop gateways like this as long as default gateway IP information is configured correctly.

    I would however suggest that instead of (own router) you simply buy a decent home networking switch and a wireless access point if necessary.

    Hope this helps.

  19. Hi there,

    I’ve just been given a link to this topic.
    I joined Sky several months ago and they provided the same Sagem router.
    The problem I’m having is that one of my network devices, a Sonos music system, cannot find the iTunes library or any other music files on my iMac.
    Extensive searching of forums has revealed there are similar issues with home networking, using NAS devices etc, being reported by many Sky broadband customers.
    Having explored all sorts of possibilities, I now know the problem is down to the router.

    The solution you suggest seems to answer my problem, however I am on Sky Fibre broadband with a BT Openreach modem and the Sky Sagem router’s modem function being bypassed.
    Would there be any problem with adding my own router as suggested, with this configuration (i.e. Openreach modem – Sky router – own router), or would the Sky router simply become a gateway?
    Does this change the suggested set-up as described by you?

  20. Thank you for the reply.
    I have now installed a 5 port Gigabit Switch, connected to the Sky Sagem router and have the current “wired” devices (iMac and Sonos Bridge) connected here.
    It makes no difference compared to connecting everything directly to the router. This appears to be a common issue with the Sky router.

    Sonos can access internet radio and online music streaming services. It can also receive updates etc.
    The Sonos control app on the iMac works perfectly normally and using the Sonos wireless controller (which operates on the Sonos Mesh network and not the home WiFi) instantaneously updating the control app on the iMac; i.e. they both operate in sync. The same for the iPhone and iPad apps running via WiFi.
    So clearly there is communication across the router (and the Switch, when it was introduced into the set-up).

    The problem is that the Sonos cannot access the iTunes library hosted on the iMac and both the automatic set-up for accessing the library and manually assigning the location, fail with an “xxx’s iMac cannot be found” error message.
    This is the same problem as other Sonos users are experiencing with the same Sky router.

    The other thing I’ve noted, is that in the routers control panel, connected devices do not have names in 9/10 cases, being displayed as “unknown”, rather than “xxx’s iMac” or “Joe’s iPod” etc.
    Occasionally a couple of names will be displayed, but others will be “unknown”.

    Everything worked perfectly with our previous router and I could share files and music with my daughter’s laptop, which I cannot do now with the Sky router.
    Having reconnected it, it still works OK; so the problem is clearly down to the Sky router.

    I intend to install a NAS device, both to host my iTunes library and other media and data files, hence the Switch; but there are numerous reports that the same issues affect using a NAS with the Sky router. “xxx-NAS cannot be found”.

    Thanks in anticipation.

  21. I wouldn’t worry too much about devices not being listed in the connected list, this is all related to what information is broadcast about the device when it’s communicating with the router and probably some smart lookup feature of the router which may even use a Mac address table to guess the manufacturer when this information is not broadcast.

    Do you know if your other router can work in AP mode only? This could open up some interesting test options such as having a seperate wireless network for the Sonos…

    Sonos > AP > Switch > Sky Router > Internet

    Or even allow you to disable the Wireless on the SKY and use it for all devices for Wifi

    All Wifi Devices > AP > Switch > Sky Router > Internet
    All Other Devices > Switch > Sky Router > Internet

    Out of interest, if the internet is already presented to you by an Open Reach modem, do you need to use the Sky provided router at all?

  22. Sorry, AP mode ?
    Am I being dense here?

    Note that Sonos doesn’t use the home WiFi. It runs its own wireless Mesh network independent of the WiFi.
    One Sonos device must be connected by ethernet to the router. It cannot connect to the home network by WiFi.

    My old router is only a G and not an N. It’s range is limited and it struggles to cover the far reaches of our house, so I don’t intend to use it again.
    I’ll buy a new one if the proposed solution is to limit the Sky router to being a simple gateway.

    Forgive me for not understanding the technicalities involved, but my instinct suggests that a solution can be found by installing a new router to handle the network (wired and wireless) and DCHP. Hopefully I’ve got that right?
    My other concern is will this configuration be OK with the additional BT modem in the circuit?

    Home Network (PC’s & Mac’s, NAS, Internet radio, Sonos etc,) – new router – Sky router – BT modem – Internet

    I wouldn’t have gone with Sky if I had known that home networking is limited or not possible with their routers.
    Sky technical help have confirmed the limitations with their router and will not provide advice on work arounds (that confirms other peoples experiences as reported on various help forums).

  23. Ah I see – I haven’t used Sonos before.

    What I can tell you is that my home network is much simpler using Sky’s Hub and I’ve got no problems using iTunes to my 2 iphones / ipads, my Apple TV, streaming movies from my server to my DNLA DVD player etc. So unless this is something specific to Sonos I haven’t experienced yet – I can’t find fault with the home networking features of the Sky Hub.

    The thing I’m still not clear on is if your external IP is presented by the BT modem, why you would need the Sky Router at all? I understand the need for the Sky device on an ADSL circuit due to the authentication etc, but I’m unsure why the modem cannot provide you with a connection that any router could just connect to – do they insist on their product even on Fibre? Is there additional authentication?

    If the Sonos doesn’t need wireless and has an Ethernet entry point into the network – I would just suggest you could test your network without the router (or Internet connection) and connect everything into your switch. If this doesn’t work – it may be that there is a deeper issue than Sky’s kit.

  24. For Fibre services, including FTTC, BT OpenReach do the installation and setting up of the fibre service, regardless of the ISP.
    There is no self-install option as far as I’m aware.

    I don’t know why they require the BT modem as well as Sky’s router, unless it’s either a contractual thing, where OpenReach are responsible for the line all the way to the terminal in the premises (i.e. the modem), or if it’s because the supplied modem is set up for the fibre service in some way?

    As I said in earlier posts, the issue doesn’t appear to be specific to the Sonos system, judging from other peoples problems with the Sky Sagem router. It appears you can’t install a NAS in the normal manner either and others report “xxx PC/Mac not found” when attempting to set up file sharing.

    I wondered if the new Sky Hub would solve the problem, but Sky support said that it’s set up the same way. They are not allowed to provide help on these sort of issues and point customers in the direction of the “internet community”, or the support services for your own computers or devices. Some support service !!!!!

    I have wondered if Sky have done this deliberately to stop people using their online viewing services and porting them around the home, thus avoiding paying for the Sky TV multi-room service?
    I haven’t thought that through yet though; it’s just a wild guess?

    The bottom line is if I can introduce my own router into the network, to perform all the usual router duties and relegate the Sky router to gateway status, then I will go with that solution.
    My concern is will it work and how do I set it up?

    Thanks for any help you can offer.

  25. I don’t recall running into any specific sharing issues when I had the Sagem either and I use a number of services including local streaming from my server to my tv, dvd player, idevices and Apple TV. Wonder what it is or what protocol is being blocked – can’t say I’ve had the same issues.

    My thoughts of just running the switch without a router would at least prove there is no deeper issue in your network.

    As for going with a multi homed system – if the Openreach Modem is doing nothing other than presenting the line, the system of having your Sky Router up front doing nothing other than being a gateway to your own router should work without issue.

  26. Thanks for your help.

    I ‘ve now found some additional information on obtaining the router’s Sky PPP username and PPP password using an online calculator. Apparently these can be used to form the key to set the DHCP client ID on a non-Sky router.
    That would allow the use of a suitable router of your choosing, rather than the Sky supplied item.

    I haven’t checked, but I guess that’s outside the Sky T&C’s though?

    1. You’re very welcome.

      I think it’s always been possible to use other routers, even with the additional levels of security that MER brings but I do believe this is against Sky’s t&c’s and not something I have done before.

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