Tweak Fritz!Box for AirPlay across ethernet and wifi

  1. Intro
  2. tl;dr – Configuration
  3. Related stuff


By default the FritzBox 7390 does not forward multicast (or mcast) packets between wifi and ethernet, sometimes it won’t work over ethernet entirely. As long as all your multicast gear is connected over wifi this should not be a problem for protocols like Apple’s AirPlay and AirPrint. When your printer and Raspberri Pi with Pi MusicBox are on ethernet and the rest is on wifi this is a big annoyance because my iPhone won’t receive the Bonjour details from the hardwired devices.

I had to do the steps below to finally enable full multicast support on the whole network.

tl;dr – Configurationmini_rj11_phone_keypad

1. Plug in an analog phone or similar device to one of the rj11 FON ports.

2. Dial #96*7* to activate telnet.

3. Telnet to and login.

4. First enable for the running system: ifconfig lan allmulti

5. Add that command to boot script: echo 'ifconfig lan allmulti' >> /var/flash/debug.cfg

In case of error can’t open ‘debug.cfg’ create the file:

  1. nvi /var/flash/debug.cfg
  2. Type i and then #!/bin/sh [enter]
  3. Type ifconfig lan allmulti
  4. Hit esc key and type :w [enter] :q! [enter]

6. Then exit, ctrl + ] and quit

7. Dial #96*8* to disable telnet.

I wonder why such a simple trick is not implemented by default…

Update 2015-01-11
Fixed wrong bash bin: /bin/bash must be /bin/sh

4 thoughts on “Tweak Fritz!Box for AirPlay across ethernet and wifi

  1. Hi Franklin,

    I tried to setup telnet as you described.

    Since firmware 6.25 AVM disabled telnet. I can see “telnetd on” on the display of my telephone. When I try to setup a telnet it tells me connection refused.

    I read some posts about glassfiber connected directly to LAN1 port of my 7490 and no separate LAN ports for internet (VLAN4) and IPTV (VLAN6). For IPTV I read multicast is necessary, so it should be on already.

    1. Hi, I’m on FritzOS 6.30 and telnet works just fine, do you connect to TCP port 23?

      Your uplink should indeed be connected on LAN1, but IPTV is only available on LAN4. I don’t have IPTV enabled on my fritzbox.

  2. An interesting post Franklin.

    What does your network look like?

    I just got a Fritzbox 7490 and try to get it working with an AirPort TimeCapsule and AirPort Extreme. If I put both my Apple router as access points in bridge mode. Is it possible for the Fritzbox to support AFP, Airplay, Airprint, Bonjour, multicast DNS with your post settings?

    Thanks in advance

    1. I have a Fritzbox 7390 as router, a ProCurve 1810G as switch and Apple TV and Brother printer (and more stuff) wired through the switch. The Apple TV for Airplay streaming and the printer has Airprint support.

      I believe all Apple devices have multicast forwarding enabled by default. When you put them in bridge mode it should all work fine. But be sure the Fritzbox is the only active router in your network.

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