Mario MG

Q: AppleTV 3 floods DHCP when ethernet connected

I am hoping others can open a case with Apple for this, you may not be aware this is happening.

 

The AppleTV 3 with 7.0.2 or 7.0.3, and connected via ethernet will (may?) flood your network with DHCP request. That is, it makes a DHCP request every 2-6 seconds instead of once or so a day. This does not happen if connected via wifi. I have a log sent by my router (Zyxel) once a day and prior to the ATV 3 it was 1 page long, now it is 50 pages long! 99 percent of it is the ATV 3 sending DHCP requests. If you don't have a way of monitoring your network you may notice this is happening so you'll need to log/monitor this to see it. If you have the problem please open a case with Apple as I have done since Apple Feedback does not help fix thing in a timely fashion. My understanding is that this was known and fixed in 7.0.3 but only for wifi connections. I have the house wired for cat 6 and want ethernet for our primary ATV 3.

 

This does not happen to our ATV 3s connected via wifi and our older Apple TV 2s.

Posted on Feb 13, 2015 12:18 PM

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Q: AppleTV 3 floods DHCP when ethernet connected

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  • by benji888,

    benji888 benji888 Feb 14, 2015 6:54 PM in response to Mario MG
    Level 1 (4 points)
    iPhone
    Feb 14, 2015 6:54 PM in response to Mario MG

    (ATV3 ethernet connection here)

    Interesting, I was having slow internet recently, wondering if ATV3 was doing something like this in background...I unplugged it, but reset everything else too, so not sure if it was the culprit. (We might have too many devices for our 10M DSL.)

     

    I have a different router, but, I know how to go into it and change settings, do they all have an option to log and send this info.?

     

    I've also wondered about my iPhone with WiFi calling, if it's doing something similar, or iCloud...with my Mac or iCloud in general (with all my devices).

  • by RWP123,

    RWP123 RWP123 Feb 14, 2015 8:13 PM in response to Mario MG
    Level 1 (0 points)
    Feb 14, 2015 8:13 PM in response to Mario MG

    Thank you so much! You are absolutely correct. I was having a problem using Airplay from my Mac Mini (late 2012) to my ATV3 while both were connected by ethernet. I could get sound but only a grey screen on my TV. I tried everything I could think of to correct it, but nothing worked. I checked all the forums, but yours is the first solution I have seen. I changed the ATV3 to wifi and now everything is back the way it was.

     

    My iPad and iPhone continued to have access to Airplay, only the Mini had problems.

     

    What is the easiest way to open a case with Apple?

     

    Don't they check their updates before they release them?

  • by Willie Strickland,

    Willie Strickland Willie Strickland Feb 15, 2015 3:10 AM in response to Mario MG
    Level 1 (15 points)
    Feb 15, 2015 3:10 AM in response to Mario MG

    I Have a dedicated IP address on the LAN for my AppleTV 2.  Have you tried that?

  • by benji888,

    benji888 benji888 Feb 15, 2015 8:26 AM in response to Mario MG
    Level 1 (4 points)
    iPhone
    Feb 15, 2015 8:26 AM in response to Mario MG

    I have looked all through my router, can't find a way for it to send me those logs. Not sure I even see those logs, I see what devices have DHCP leases and what IP add they have, but, it's just a list of what's connected (IP/MAC add/expires), and there is a system log, but, it's not in order by date, and I can't find options to have them sent to me.

     

    I'm using a (T-mobile) ASUS TM-AC1900 router. If you can help me find these specific logs, or how to have them sent to me daily, I will do my best to set that up.

  • by Mario MG,

    Mario MG Mario MG Feb 15, 2015 10:29 AM in response to RWP123
    Level 1 (27 points)
    Apple Pay
    Feb 15, 2015 10:29 AM in response to RWP123

    To open a case got to http://www.apple.com/support/contact/ it's free and easy, they call back in minutes, you will then have to convince the first level person to send you to a "specialist" who will document your issue and send it to engineering, enough of us complain and they will notice. I have sent them logs and even port mirroring traces, I spent several days on this. The trace and logs clearly show the problem. BTW, even though DHCP requests are flooding it gets the same address each time. Another really odd thing I found which may explain AirPlay problems (I have them) it that the ATV 3 actually shows up in the trace with TWO IP addresses! One floods and the other shows up a lot but led frequently. I sent Apple the trace to prove it.

     

    BTW, most people won't see/notice this because they don't have router logs. Also, I have an HP switch that allows port mirroring so I can monitor all network traffic to/from the ATV 3 using Wireshark (I used Linux but it works on Mac).

  • by Mario MG,

    Mario MG Mario MG Feb 15, 2015 10:33 AM in response to Willie Strickland
    Level 1 (27 points)
    Apple Pay
    Feb 15, 2015 10:33 AM in response to Willie Strickland

    This is a DHCP flooding problem so DHCP would not be used if the ATV 3 had a static address. I have 45+ IP addresses in my house so static IPs are not practical and too much work if/when I change something.

  • by satcomer,

    satcomer satcomer Feb 15, 2015 11:15 AM in response to Mario MG
    Level 4 (1,110 points)
    Feb 15, 2015 11:15 AM in response to Mario MG

    If I were you I would go into the router settings and give the IP of the AppleTV and give it a DHCP Reservation,  this might help.

  • by benji888,

    benji888 benji888 Feb 15, 2015 12:16 PM in response to Mario MG
    Level 1 (4 points)
    iPhone
    Feb 15, 2015 12:16 PM in response to Mario MG

    "BTW, most people won't see/notice this because they don't have router logs. Also, I have an HP switch that allows port mirroring so I can monitor all network traffic to/from the ATV 3 using Wireshark (I used Linux but it works on Mac)."

     

    Mario MG Help:

     

    I have several logs, not sure if any will show this. One is called System Log - Active Connections, the last column is "State" - Enabled/Assured/Unreplied/Time Wait/Close. Apple TV is in this list most, but, not sure what this is showing me?

     

    The General Log is a bit scattered. The System Log - DHCP Leases which shows current connections and expirations, just lists each device, doesn't show when lease was activated.

     

    This router has a lot to it, but, not sure if any of these are showing me how often DHCP leases are asked for, any clues?

  • by Drew Reece,

    Drew Reece Drew Reece Feb 15, 2015 1:00 PM in response to Mario MG
    Level 5 (7,490 points)
    Notebooks
    Feb 15, 2015 1:00 PM in response to Mario MG

    DHCP requests from devices are sent to the broadcast address on that network range. Any device on the same wired network should see these packets. I don't think you need to setup port mirroring or router logs to see a device flooding requests for a DHCP lease. I may be wrong - I have a router that may be acting as dumb hub.

     

    Terminal on a Mac on the same wired network…

    ifconfig
    

    …to see your interfaces list - work out which one is the ethernet on your Mac (it should be UP & have an IP address - compare it to your network settings if you are unsure).

     

    Mine is 'en0' so in an admin account…

    sudo  tcpdump -plenXX -i en0 -s 1500 port bootps or port bootpc
    

    To confirm this is working, power off the ATV, unplug another device that is on ethernet & reconnect it - you should see the request for a lease.

    Power up the ATV - now you should see a lot of traffic for the ATV if it it is flooding for leases.

     

    If you see nothing at all - I may be an idiot, let me know

     

    NOTES

    You will not see the reply sent to devices from router - you need promiscuous mode for that.

    You won't see requests for wifi connected devices either this is for ethernet testing.

     

    @Mario MG, consider removing the port mirroring connection as a test - it may be part of your issue.

  • by RWP123,

    RWP123 RWP123 Feb 15, 2015 3:19 PM in response to RWP123
    Level 1 (0 points)
    Feb 15, 2015 3:19 PM in response to RWP123

    Thank you so much! You are absolutely correct. I was having a problem using Airplay from my Mac Mini (late 2012) to my AT3 while both were connected by ethernet. I could get sound but only a grey screen on my TV. I tried everything I could think of to correct it, but nothing worked. I checked all the forums, but yours is the first solution I have seen. I changed the AT3 to wifi and now everything is back the way it was.

     

    My iPad and iPhone continued to have access to Airplay, only the Mini had problems.

     

    What is the easiest way to open a case with Apple?

     

    Don't they check their updates before they release them?

  • by benji888,

    benji888 benji888 Feb 15, 2015 8:37 PM in response to RWP123
    Level 1 (4 points)
    iPhone
    Feb 15, 2015 8:37 PM in response to RWP123

    "I was having a problem using Airplay from my Mac Mini (late 2012) to my AT3 while both were connected by ethernet. ... I changed the AT3 to wifi...."


    This is not a solution, just a workaround.


    I have my (mid 2010) MacBook Pro and ATV3 connected via ethernet to my router, iOS devices over wifi and they can all airplay to the apple tv, also home sharing iTunes works fine. You should be able to airplay from your Mac Mini to the apple tv using ethernet connection with apple tv & mac. You should also be able to access your computer's iTunes library from the ATV3 if you have home sharing enabled.


    The first thing I would try is unplugging the ATV (power). The ATV only goes to sleep unless you either manually restart it or unplug it. I would also try, on your Mac, sign out of iCloud, sign back in...this can solve some connectivity issues with Macs. The problem is somewhere between the mac & the apple tv. In fact, now that it works over wifi, if your ethernet cables are still hooked up, try turning wifi off on the mac and use wired connection for the atv, it might work, electronics are strange this way.

  • by RWP123,

    RWP123 RWP123 Feb 15, 2015 9:05 PM in response to benji888
    Level 1 (0 points)
    Feb 15, 2015 9:05 PM in response to benji888

    Sorry about my double post - I got interrupted.

     

    You are right, it was only a workaround, in fact the connection over wifi no longer works (worked yesterday, not today!). All my iOS devices can use airplay, my Mini is connected by ethernet to the ATV 3, and iTunes works with home sharing from the Mini. I see a fixed screen or a grey screen depending on whether I use ethernet or wifi from the Mini to the ATV 3 whenever I use airplay. The really annoying thing is that this all used to work so well, and I have done nothing except keep all my software up-to-date.

     

    I will do as you suggest and let you know what happens. Many thanks for the help.

  • by satcomer,

    satcomer satcomer Feb 16, 2015 1:52 AM in response to Drew Reece
    Level 4 (1,110 points)
    Feb 16, 2015 1:52 AM in response to Drew Reece

    Yea Drew you are using outdated Mac Terminal commands. Learn the OS X command networksetup. So just man networksetup to find some heavy commands.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 16, 2015 2:41 AM in response to satcomer
    Level 5 (7,490 points)
    Notebooks
    Feb 16, 2015 2:41 AM in response to satcomer

    ifconfig may old, but it's just another bsd tool that is still built in. I've always hated networksetup, all of it's arguments are too long

     

    networksetup -listnetworkserviceorder

     

    networksetup -help

    … 400 lines

     

    networksetup -printcommands

    …100 lines

     

    bleargh

     

    ifconfig isn't editing anything here so ifconfig isn't terrible here is it?

     

    @benji888,

    To remove the router from the equation connect the ATV to your Mac via ethernet.

    Enable internet sharing on the Macs ethernet port (you do not need an active internet connection, sharing still activates the OS X DHCP server).

    Now tcpdump or use Wireshark on the ethernet (or the prettier CPA).

    The ATV should flood the Mac's ethernet - if it doesn't there could be a different interaction on the router or network.

     

    You don't need a days worth of logs, a few minutes of capture should show the ATV is malfunctioning.

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