mumbles2701

Q: Hard Wired Static IP Mini Disconnects from Network

Hi Forum,

 

 

i have a Mini that is hard wired to the router, and has a static IP address. the Mini is left on all the time as i access it and its drives remotely.

 

what i find is that after a few days it loses connectivity to the net. To get connectivty back i have to restart the Mini. Even rebooting the Router doesnt work. Any ideas what this could be? Why does it disconnect itself? Or could it be the router erring? Any tools to use to tell?

Mac mini, OS X Mavericks (10.9)

Posted on Oct 15, 2014 1:22 AM

Close

Q: Hard Wired Static IP Mini Disconnects from Network

  • All replies
  • Helpful answers

  • by mumbles2701,

    mumbles2701 mumbles2701 Dec 24, 2014 7:14 AM in response to mumbles2701
    Level 1 (9 points)
    Apple TV
    Dec 24, 2014 7:14 AM in response to mumbles2701

    did anyone read this?

     

    its doing it again. its hardwired to the new BT Router [UK] and has a static IP assigned, and all the settings within System Settings adhere to the router, the IP address of the router, etc. everything else on the network, including wireless and hardwired stuff works.

     

    confused isnt the word!?!?!

     

    even connection Assist Me Diagnosis button on the connection settings tells me 'internet' and 'server' have failed?!?!?! everything esle is green and ok?!?

     

    odd.... anyone?

  • by mumbles2701,

    mumbles2701 mumbles2701 Apr 2, 2015 12:30 AM in response to mumbles2701
    Level 1 (9 points)
    Apple TV
    Apr 2, 2015 12:30 AM in response to mumbles2701

    Still having problems with this. Now it seems that Screen Sharing has an issue with BT Broadband. But also something seems to happen on reboot when the message asking about keyboards comes up, Screen Sharing doesnt become available [on the odd chances it does work with BT] and my Tamviewer account wont connect either...

  • by BobHarris,

    BobHarris BobHarris Apr 2, 2015 5:45 AM in response to mumbles2701
    Level 6 (19,272 points)
    Mac OS X
    Apr 2, 2015 5:45 AM in response to mumbles2701

    This is most likely NOT your problem, but I'll throw it out there anyway.

     

    Many times not connected to the internet is a problem with the DNS servers assigned by the ISP, or with the router that frequently acts as a local DNS server for the home LAN.  Since most network connects start by translating the target host name to an IP address, if the DNS servers fail, the connection never gets off the ground.

     

    The test for this is to set your own DNS servers via System Preferences -> Network -> Advanced -> DNS -> [+]

    OpenDNS and Google DNS servers are reliable substitutes:

     

    OpenDNS.org 

    208.67.222.222

    208.67.220.220

     

    Google DNS

    8.8.8.8

    8.8.4.4

     

    Again, I do not really think this is your problem, but it is an easy test to try.

     

    After that I would try a different Ethernet cable to eliminate that as an option.

     

    Do you run any anti-malware, or Little Snitch, a 3rd party firewall, etc... that might interfere with network connections?

     

    I would boot into Safe Mode, to hopefully eliminate any 3rd party additions

    <http://support.apple.com/kb/ht1564>

    such as anti-malware, 3rd party firewalls, little snitch, etc....

     

    You said new BT Router.  Did this problem start when the new BT Router was setup, or did this happen with the previous router?  If you can isolate this to a single equipment (or software) change that might help narrow down the search for what is causing the problem.

     

    The static IP address.  Is it in the range of IP addresses the BT Router assigns via DHCP?  Is it possible the BT Router assigned your IP address to another device (a smart phone, another computer, to a neighbor while it was asking for the network password, etc...  Or have you configured the BT Router to always give your Mac mini the same fixed IP address, so the BT Router will not give that address out to any other device.

     

    Those are all my guesses.  I hope something I suggest gives a clue to what might be happening.

  • by mumbles2701,

    mumbles2701 mumbles2701 Apr 8, 2015 4:25 AM in response to BobHarris
    Level 1 (9 points)
    Apple TV
    Apr 8, 2015 4:25 AM in response to BobHarris

    im not sure if this is related or i should start a new thread but I have BTMM issues also. It never seems to be availble when i'm remote... like now. I use it to do things on my Mini remotely. A lot of times i end up using Teamviewer as BTMM isnt available and i dont know why.

     

    If i change my DNS does it affect anything? if im remote will it throw me off the connection?

     

    i have no Malware software

     

    The disconnection happened with both old and now new router. the BTMM issue also happens with both old and new, but seems more prominant with new. I think i get less network disconnections but more simple BTMM not available. i think on old router the non available BTMM was due to network disconnection. Now i dont get Netowrk Disconnection much [as i see Teamviewer is available on that Mini] but BTMM is never available???

  • by BobHarris,

    BobHarris BobHarris Apr 8, 2015 6:25 AM in response to mumbles2701
    Level 6 (19,272 points)
    Mac OS X
    Apr 8, 2015 6:25 AM in response to mumbles2701

    It is possible the BTMM is related, if the problem child is the BT Router.  BTMM depends on being able to tell the router to open a port on its behalf.  BTMM uses Universal Plug and Play (UPnP) or NAT Port Mapping Protocol (NAT-PMP) to open that port (from Wikipedia).

    <http://en.wikipedia.org/wiki/Back_to_My_Mac>

    You router needs to support one of these AND it has to be enabled (some routers have the ability to disable these features for security reasons).  I TeamViewer.com use an entirely different method to make its connection, which is why it would not have the same problems as BTMM.

     

    All of the above is just a guess as to what might be happening (I do not use BTMM, so I mostly going on general knowledge).  Here are more BTMM links

    Set up and use Back to My Mac - Apple Support

    If you have issues using Back to My Mac - Apple Support

    You might try some other Google searches on "troubleshooting back to my mac"

     

    If i change my DNS does it affect anything? if im remote will it throw me off the connection?

    No.  But, I still do not think DNS is your problem, so I would wait until you are home and not worried about loosing a remote connection to the Mac. The DNS server is basically a telephone book that converts host names to IP addresses.  When you change it, it will affect the next www.company.com translation to a 11.22.33.44 address.  Besides this is just an experiment.

    i have no Malware software

    Good.  The long term forum contributors do not really like the Mac anti-malware products, as they then to be written for Windows, then badly ported to Macs where they spend most of their time scanning for WIndows virii, slowing down the Mac, blocking network connections, and causing kernel panics.  So not having 3rd party anti-malware is one less thing to worry about.  Mac OS X has it is own anti-malware features:

     

    How does Mac OS X protect me?

     

    <http://www.thesafemac.com/mmg-builtin/>

     

    I still do not know what is happening, but the BTMM not working makes me want to suspect the BT router (easy for me to say, from 1000's of miles away ).

  • by VikingOSX,

    VikingOSX VikingOSX Apr 8, 2015 7:09 AM in response to mumbles2701
    Level 7 (20,606 points)
    Mac OS X
    Apr 8, 2015 7:09 AM in response to mumbles2701

    Could it be that your static ip address is within the DHCP assignment block of addresses, and randomly, the router attempts to assign an IP address that matches your static, and this collision disconnects your mini?

  • by mumbles2701,

    mumbles2701 mumbles2701 Apr 9, 2015 1:46 AM in response to VikingOSX
    Level 1 (9 points)
    Apple TV
    Apr 9, 2015 1:46 AM in response to VikingOSX

    just so i'm clear, and i cant check now as not home till Saturday, the DHCP assignment should be something like 192.168.1.100 to 192.168.1.253, i think the router is 192.168.1.254, then anything with a static IP should be outside of this, so 192.168.1.1 to 192.168.1.99?

     

    so my Mini which is hard wired and has a static IP should be within 192.168.1.1 to 192.168.1.99?

     

    Does static include all wired devices? or do they get a DHCP assigned IP each time they switch on and off?

     

    My Mini was doing some iPhoto Library Merging yesterday [perfect thing to get it ot do while away] and now its suddenly not available on BTMM [which it wasn't anyway] or Teamviewer

  • by BobHarris,Helpful

    BobHarris BobHarris Apr 10, 2015 12:06 AM in response to mumbles2701
    Level 6 (19,272 points)
    Mac OS X
    Apr 10, 2015 12:06 AM in response to mumbles2701

    just so i'm clear, and i cant check now as not home till Saturday, the DHCP assignment should be something like 192.168.1.100 to 192.168.1.253, i think the router is 192.168.1.254, then anything with a static IP should be outside of this, so 192.168.1.1 to 192.168.1.99?

    Please verify those values.  Most of the routers I've worked with use the 192.168.1.1 for the router address (a convention, and NOT a hard rule).  But it is possible to have a router use 192.168.1.254 for its address.  But it would be good to verify.  I suppose you could actually do that via TeamViewer.com, but since you are on the road, you time may be limited and I'm not in the business of scheduling other people's time

     

    Does static include all wired devices? or do they get a DHCP assigned IP each time they switch on and off?

    There are roughly speaking 3 approaches to IP address assignments (2 DHCP variations, and a Client specified Fixed IP)

     

    DHCP is the client making a DHCP query to find the DHCP server on the local network (and there should be ONLY 1 DHCP server on the local network). The DHCP server responds and assigns an IP address to the Client, along with telling the Client the router address the network mask, and the DNS servers to use.

     

    There have been situations where 2 routers have been put on the same network and someone forgets to turn off the DHCP server on the 2nd router, then you have fighting DHCP servers that are giving out the same IP addresses.  If you have more than one WiFi base station, you may want to make sure you do not have 2 DHCP servers in operation.

     

    DHCP Server assigning the Same IP address.  In this situation, the router is configured to always give a Client with the same identifier the same IP address when the Client makes it DHCP query.  Some Routers using the client's MAC (Media Access Control) nn:nn:nn:nn:nn:nn address, others use the DHCP Client ID the Client gives itself.  The MAC address is different for Ethernet and WiFi from the same Client.  A Client specified DHCP Client ID can be the same for all network interfaces if the Client is configured to use the same DHCP Client ID on all network interfaces (Apple Routers like DHCP Client IDs, most other Routers like MAC addresses).

     

    Anyway, this is a way to get a fixed IP address without worrying about the router trying to assign it to another device.

     

    Client specified Fixed IP address.  The client just configures its network interface to use a Fixed IP address.  It does not check with anyone, and if the IP address is in use somewhere else there is nothing to stop the client from using the IP address.  This requires careful network management on the part of the local network admin (I'm guessing this is you).  If another device uses that same IP address, it can cause all kinds of fun and games on the local network, generally not good.

     

    I used to used fixed IP address, but once handheld smart devices started entering the house, and I had to manage 8 or 9 IP addresses, and new Macs entered the home, old Macs were giving new dedicated tasks, or removed from service, keeping track of the IP addresses assigned got to be a pain.

     

    Now I tell the router I want it to assign an IP address to a specific Mac and all the assigned IP addresses are in one place.  Plus when my laptop is home it has a fixed IP address, but when I'm in a coffee shop I do not need to mess with my network setup to change from a fixed to a DHCP assigned address.

     

    To answer you question about WiFi vs Ethernet, if you have both active AND connected, AND both use DHCP, then they both get an IP address.  If you have configured them BOTH with static IP addresses, then they use that IP  address.  If one is static and one DHCP (and again both connected), then the static uses it static IP and the DHCP one gets an IP address from the router.

     

    HOWEVER, Apple has a network priority order, and ONLY uses the highest priority network interface which is connected.  By default Ethernet (because of its higher speed) is of higher priority than WiFi.  The WiFi would only kick in if the Ethernet became inactive.  System Preferences -> Network -> Gear icon -> Set Service Order...

    Screen Shot 2015-04-09 at 1.44.10 PM.png

  • by mumbles2701,

    mumbles2701 mumbles2701 Apr 10, 2015 12:14 AM in response to BobHarris
    Level 1 (9 points)
    Apple TV
    Apr 10, 2015 12:14 AM in response to BobHarris

    sounds like my network si ok according to this. the only static IP is my Mini, which is hardwired to the router, but the assigned IP is '.70'. Looked at my range the other night and BT Router is infact .254, the DHCP range is .64 to .253.

     

    so my Mini being .70 and inside the DHCP range should not affect its connectivity?

     

    and all other setitngs such as priority are correct

  • by BobHarris,

    BobHarris BobHarris Apr 10, 2015 5:58 AM in response to mumbles2701
    Level 6 (19,272 points)
    Mac OS X
    Apr 10, 2015 5:58 AM in response to mumbles2701

    the only static IP is my Mini, which is hardwired to the router, but the assigned IP is '.70'. Looked at my range the other night and BT Router is infact .254, the DHCP range is .64 to .253.

     

    so my Mini being .70 and inside the DHCP range should not affect its connectivity?

    If the .64 to .253 is NOT a typo, then .70 is in the middle of the DHCP assigned range, and it is very possible for your BT Router to assign that IP address to another device (a smart phone, a tablet, a WiFi gaming device, a smart TV, an Apple TV, etc...).

     

    I would suggest looking to see if you can get the BT Router to assign your fixed IP address to your Mac mini.  Often times this is called "reservations", but it could be labeled something else.

     

    Or I would put the Mac mini "Outside" the BT Router DHCP address range.

     

    Or I would change the BT Router DHCP address range to start After your Mac mini fixed IP address.

  • by mumbles2701,

    mumbles2701 mumbles2701 Apr 13, 2015 6:50 AM in response to BobHarris
    Level 1 (9 points)
    Apple TV
    Apr 13, 2015 6:50 AM in response to BobHarris

    thanks BobHarris

     

    currently the Mini has become non contactable via Teamviewer, BTMM outsdie or insid my network, while carrying out some major iPhoto maintenance which is very frustrating. Ive had to order a 20m HDMI lead to connect it to my TV in another room so i can see whats its doing or why its stuck. I cant turn it off and move it as i risk recorrupting the iPhoto DB, which is whats happened previously hence the maintenance..

     

    sort of makes the Mini useless to being a headless media system when it keeps doing this.

     

    once the lead arrives and i get home next weekend, i'll report back

  • by VikingOSX,

    VikingOSX VikingOSX Apr 13, 2015 7:22 AM in response to BobHarris
    Level 7 (20,606 points)
    Mac OS X
    Apr 13, 2015 7:22 AM in response to BobHarris

    So, I see the OP is camping his mini in the middle of the DHCP range, after all.  Good suggestion on DHCP reserved assignment — if the router supports it. Strange that .254 for the router though.

  • by mumbles2701,

    mumbles2701 mumbles2701 Apr 13, 2015 7:26 AM in response to VikingOSX
    Level 1 (9 points)
    Apple TV
    Apr 13, 2015 7:26 AM in response to VikingOSX

    standard for UK BT service it seems...

     

    you agree i should change my Mini to something like .50 so its outside the DCHP range? I'm not sure why its inside, i put it there for a reason, maybe something i read previously...

     

    and 'OP'...? whats that?

  • by BobHarris,

    BobHarris BobHarris Apr 13, 2015 7:57 AM in response to mumbles2701
    Level 6 (19,272 points)
    Mac OS X
    Apr 13, 2015 7:57 AM in response to mumbles2701

    ...i should change my Mini to something like .50 so its outside the DCHP range?

    Yes, Please.

     

    and 'OP'...? whats that?

    It is "Forum" shorthand (and not just discussions.apple.com) for "Original Post", as in the person that started the thread.