Resolved Ethernet madness - make it stop

Discussion in 'Mac mini' started by Cassady, Jan 13, 2017.

  1. Cassady macrumors 6502a

    Cassady

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    Sqornshellous
    #1
    I'm sorry for the double post - put a similar one over in the Sierra sub-forum, but I am desperate, and really, really need help!

    How does one try to change the settings of your ethernet in Preferences, when the field to input the IP address is not active for long enough before an error message "Invalid IP Address" flashes up?

    The ethernet selection jumps to green, and flashes up that it is connected. 2 seconds later, it jumps down to below Bluetooth, and reverts to red - with status being ethernet cable is not connected. Then 2 seconds later, it connects again.

    I cannot adjust anything, because this loop just goes on and on, and doesn't allow me to enter anything quickly enough to apply and save.

    Mini was always connect via Wifi, and still can - but plugging an ethernet cable in, and it goes bonkers.

    Where do I even begin?
     
  2. keysofanxiety macrumors 604

    keysofanxiety

    Joined:
    Nov 23, 2011
    #2
    Best to start with the basics, if you haven't already. When the Ethernet cable is plugged in, unplug the power from your router and leave it for 1 minute, then plug the power back in. This will reassign the IP addresses on your network and might just fix it.

    If there's still an problem, try to create a new user account on your Mac and see if the issue persists through there.
     
  3. Cassady thread starter macrumors 6502a

    Cassady

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    #3
    I have done the former, not the latter. Must mention, that DCHP is switched off on the Router, and the wifi static address is defined and working. I am typing this on it now, connected via Wifi, whilst Server keeps on belching out notifications that the Ethernet IP address has been changed, then resolved, then changed, then resolved...

    Will try and log in with a guest account, and see, then come back.
     
  4. Nermal Moderator

    Nermal

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    #4
    Unplug the cable, then try to set the IP address. You should still have the option to set it even when it's red, and with it unplugged it won't jump all over the place.

    PS. I've deleted your other thread (it didn't have any replies) - duplicate threads are not allowed. But hopefully my suggestion works :)
     
  5. Cassady thread starter macrumors 6502a

    Cassady

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    #5
    That might work, will try it now. Should I set it as the same static IP address as the wifi is using, or a different one?
     
  6. Cassady, Jan 13, 2017
    Last edited: Jan 13, 2017

    Cassady thread starter macrumors 6502a

    Cassady

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    #6
    Just did that. Thank you. Could now enter the IP address. Gave it a different one, but the same thing is happening.

    Jumping between connected, and "disconnected or the device at the other end is not responding"...

    Sigh.

    When I check the router, LAN 4's light is constant, but LAN 3, that I am trying to use now to connect the Mini is switching on and off. Will try a different LAN port out the router.

    Just did the above. No difference. Restarted both router and Mini, still hopping.
     
  7. Nermal Moderator

    Nermal

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    #7
    Hmm. Reboot into the recovery partition (Cmd-R at the chime) and see whether you get the same behaviour on the router. If so, it could possibly be a bad cable.
     
  8. Cassady thread starter macrumors 6502a

    Cassady

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    #8
    Shot. Will give that a go now.
     
  9. Cassady thread starter macrumors 6502a

    Cassady

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    #9
    Ok. In Recovery mode, Network Utility. Ethernet (en0) is selected. Ran a ping test, seemed to work with one timeout.

    But - Link Status is jumping between Active and Inactive, with IP address flipping on and off as well.

    Cable problematic?

    Should I plug in the wife's MBA to make sure?
     
  10. sublunar macrumors 6502

    Joined:
    Jun 23, 2007
    #10
    If you have another device then it's a good idea to check it. If that shows the same issues then I'd try and change the cable but also consider plugging the other end of the cable into a different port on the router if one is available to eliminate that.
     
  11. JamesPDX Suspended

    JamesPDX

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    #11
    What is your system layout? List your modem, routers, and switches. Are you in Bridge Mode between a modem and a router, double NAT? Why is DHCP turned off? -etc. Help us help you. :)
     
  12. Cassady thread starter macrumors 6502a

    Cassady

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    #12
    Appreciate all the offers!

    ISP is a wireless/wisp broadband supplier, so Ubiquiti antenna to Ethernet cable into a POE (which powers the antenna). The antenna has a device in it, which handles the DHCP, so ISP asked me to turn it off on the Asus DSL r55u router. Switched IP on router from 192.168.1.1 to 192.168.0.1. This was several months back, and all my devices have been connecting ok.

    Ethernet from POE into LAN port of router. Plan is to go with Ubiquiti AC Pro/Lite APs eventually.

    Mini was always connecting via Wifi. But with Plex server on it to connected DAS, became clear I needed to wire it. Tried several months back, and gave up. Similar issues. Want to persevere now, and get this sorted. No point in having a Mini and not connect it properly!

    Complication(?) is that I only got started on working my way through one of the Take Control books on setting up and using OSX Server (running Sierra), but ran out of time, and to be honest, was struggling to follow things, since his guide obviously doesn't take into account my IP setup running without DHCP... Made some changes, but not sure if something in Server might be interfering, so figured I would mention in.

    Bought the Mini two years ago, and never tried to wire it. Really hope I haven't had a dud Ethernet port all this time...

    Hope this explains things? This is incredibly frustrating! Appreciate you all trying to help. Especially with a SO saying (innocently?) "I thought Macs simply worked?"...
     
  13. Cassady thread starter macrumors 6502a

    Cassady

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    #13
    Will do asap!
     
  14. now i see it macrumors 65816

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    #14
    Those sound like symptoms of impending Ethernet port death. That's what my mini was doing. I finally took it in to get checked. Ethernet port dead. Old mini. No parts available.
     
  15. Cassady thread starter macrumors 6502a

    Cassady

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    #15
    What year/model was yours?
     
  16. Cassady thread starter macrumors 6502a

    Cassady

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    #16
    Ok. Relieved to confirm that plugging it into the MBP, sees exactly the same thing happening. Not as quickly as on the Mini - every 3 seconds as opposed to 1.5/2 seconds - but still the same behaviour.

    I have switched the Ethernet cable from LAN 3 to LAN 2, and rebooted etc., but no difference. Tried a different cable as well, same thing. So this looks to be an issue in settings within my home network. I am relieved that this is at least not a ethernet port issue, but now - to try and get this resolved... :(

    Thanks again for the help so far - any suggestions on where I start next?

    Would it be more sensible to first try and sort out an ethernet connection via the MBP, and thereby exclude the possibility of this being OSX Server (on the Mini) running interference?

    My gut is telling me that I am missing some fundamental point about how my settings should be, after the introduction of the [wireless broadband/192.168.1.1 >> 192.168.0.1. >> DHCP off] into the mix.
     
  17. JamesPDX Suspended

    JamesPDX

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    #17
    Is there a control panel/display on the ISP service that shows that it is indeed handling DHCP?

    Use DHCP on your computers: Go to your System Preferences<Network. Make sure ethernet service is on. Turn off DHCP on the computer. Wait a minute, then turn DHCP on and wait. Then hit "Renew DHCP Lease". See if you get new IP addresses. You IP addresses and MAC addresses between WiFi and Ethernet should come up different. Are you reserving IP addresses?

    Check your subnet mask and router address. Always turn on your computer's firewall.
     
  18. jpietrzak8 macrumors 65816

    jpietrzak8

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    #18
    Here's a suggestion from left field -- my parents were having a somewhat similar problem a few years ago, and I just couldn't find any problem with settings or cords or what-have-you. (And this was only happening to one machine; the other devices on the net worked fine.)

    But then I investigated the router for a bit, and discovered that there was a firmware update available (the router was fairly old by this point). I applied the update, and voila! No more dropped network.

    So yeah, routers can have subtle problems of their own...
     
  19. sublunar macrumors 6502

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    #19
    Second that point about routers, they are often the weak part of any setup being cheap and proprietary.

    I have tried to re-read the thread - if the OPs ISP has provided a bit of hardware at the top end of the chain that's handing out the DHCP addresses then nothing else in your system should have DHCP capability on.

    If, as implied by the OP, there is macOS Server Sierra on a Mac Mini lower down the chain (connected to your Asus router which in turn is handing off the ISP hardware) handing out IP addresses then perhaps that's causing the conflict?

    Everything else connected in to your ISP hardware would have to be set to Bridge mode I think.

    If the ISP hardware allows, I would reserve IP addresses by MAC address and let the ISPs DHCP server hand out the IP addresses.
     
  20. Cassady, Jan 15, 2017
    Last edited: Jan 15, 2017

    Cassady thread starter macrumors 6502a

    Cassady

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    #20
    Thanks - I will start digging into this now - I have a few hours of quite in the house, so will pull out the Take Control Server book, and retrace my steps to see what exactly has been enabled.

    On the earlier question of an interface to "see" what the ISP is doing - I will see what I can find out. They are at pains to point out that the purely provide the strive to get internet into the house, and do no assist with the internal network issues - but yes, I thought I had a fair idea of what I was doing before, but this change as a result of the DHCP on the front-end, by them, has thrown a proper spanner in the works...

    Related to the above - when I go into Preferences/Users/Login Options, at the bottom of the right pane - I see the following, next to "Network Account Server: [green circle] Local Server [edit] > on hitting Edit, I am met with "Local Server", and just below that - as sub-title, "Open Directory Server". When I click on "Open Directory Utility", I see three [that I recall trying to set up as per the Take Control book] listed >> "Active Directory; LDAPv3; NIS", with me being able to edit these.

    This is where my issue lies, right?

    --- Post Merged, Jan 15, 2017 ---
    It *might* be the Router firmware - but that might be due to it being in 'beta', despite being released in mid-2016. Before that, the latest firmware update was as far back as early 2015 - however, this release note seems to suggest the 2016 release fixed some important things:

    ASUS DSL-N55U Firmware version 9.0.0.4.380_3925 (Annex A)
    [Beta release]
    Security Fixed
    - Enhanced the login authentication strength and fixed CSRF related issues.
    - Fixed multiple security issues

    Enhancement:
    - Added IPv6 Passthrough support
    - Added QoS Bandwidth limiter support.
    - Added Google Domain/SELFHOST.DE and removed TZO DDNS service.
    - Improved NetworkMap.
    - Added reboot schedular.

    The ASUS team thanks Pichaya Morimoto (discovery, analysis) from the
    SEC Consult Vulnerability Lab (https://www.sec-consult.com/) for responsibly
    reporting the identified issues and working with us as we addressed them.
    So I'm figuring it would be best to leave as is?
     
  21. jpietrzak8 macrumors 65816

    jpietrzak8

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    #21
    Ok, I've read back through the messages on this thread, and I think I'm getting a handle on your layout. It looks like this, right?

    1) WISP signal -> Ubiquity antenna

    Antenna contains router with address 192.168.1.1, performing DHCP

    2) Antenna -> POE -> Asus DSL-N55U

    The DSL-N55U receives signal from Antenna, accepting DHCP-defined address on 192.168.1.x range
    The DSL-N55U then performs routing on 192.168.0.x range (with its own address being 192.168.0.1).
    DHCP is turned off for the 192.168.0.x range? (Not sure why you'd need to do this)

    3a) Asus DSL-N55U -> wireless client (works correctly)
    3b) Asus DSL-N55U -> wired client (fails)

    Is this correct?

    So, now I've got more questions. :) One, I see no reason why you need to turn DHCP off on the Asus router. It should have no problem accepting a DHCP address from the antenna on 192.168.1.x, while at the same time serving DHCP on the 192.168.0.x range.

    Two, I don't really understand why having a plex server demands a wired connection (although I don't use plex myself). Most media streaming tasks can be performed quite adequately over wifi these days. :)

    But three, the error message "invalid IP address" now seems a bit more interesting to me. I would imagine you've already checked to make sure the addresses you are creating stay within the 192.168.0.x range, right? :) Also, that you don't have two devices sharing the same address.

    I took a look at the manual for the DSL-N55U; my own router provides the ability to partition the address range into some statically defined addresses, and some DHCP-controlled addresses. It looks like this router has that ability as well, but I guess it wouldn't be active if you have DHCP turned off.


    In any case, I don't think it would hurt to try updating the firmware, but I think there may still be other avenues to explore before doing that... :)

    EDIT: By the way, you wouldn't happen to have defined the same static IP address on your Mac for both wireless and wired connections, right?
     
  22. Kaida macrumors regular

    Kaida

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    Singapore
    #22
    Was it ever working with the same router before on lan? Easiest way to check where the problem lies would be to try it on another router (preferably of another make/brand) or change a lan cable.
     
  23. Cassady thread starter macrumors 6502a

    Cassady

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    Sqornshellous
    #23
    YES - thank you! You have my setup 100% correct.

    Re your questions:

    1.) Switching OFF DHCP on Asus: I have no idea - I simply followed the instructions of the ISP. They seem to stem from them having issues in the past, where DHCP was left on, on the device.

    I popped up a query about it on one of my local tech websites - one kind soul who presumably also works at a local WISP, responded with this [iBits is who I use]:


    We know a little of what's going on, on their network as we speak with them at least once a day, every day.

    iBits have a nice block of public IPv4 addresses. They also have a block of IPv6 addresses.

    Like us, they spend most every night converting clients from "192.168" address to public IP addresses.

    Like us, they use a combination of router on the roof and wireless AP in the house.

    We mostly use Mikrotik on the roof, but also use Ubiquiti in some areas. They mostly use Ubiquiti.

    If there's a Mikrotik on the roof, we'll either put a TPLink or a couple of Ubiquiti UniFis inside. This is a recipe we've used for years. It works.

    The theory is that the radio on the roof does the PPPOE connection back to the ISP. All our new clients receive a static public IP address at this point.

    Believe it or not, but iBits have a massive network. Switching all the users over is taking a very long time. The way I understand it, they have rolled out static publics to the towers / PPPOE concentrators, but are still rolling public IPs out to the clients. At this point the PPPOE should therefore receive a 192.168 address that is NATted. Now, if your router on the roof does all the DHCP and your router in the house is a dumb bridge, you don't have a double NAT situation.

    You don't want a double NAT. This is bad.

    We normally pop a RJ45 connector into the TPLink or Tenda AP's WAN port to block it. Then the AP receives a static ip of 192.168.1.1 with gateway 192.168.1.254 and DHCP is switched off.

    The TPLink or Tenda is then a dumb bridge. It does no work, apart from wifi and network switch. These things don't have the fast processors you find in Routerboards. Switching from router to dumb bridge means our clients (and iBits' clients) can now have speeds of 30Mb+ over wireless on relatively inexpensive kit.

    The router on the roof then does the DHCP and NAT's the 192.168.1.x network to the WAN IP address of the router.

    For the techs... The other reason both us and iBits are doing this, is ease of implementation of IPv6. All we need to do is have a static IPv6 address in one /64 on the WAN port and another IPv6 address on another /64 that advertises on the LAN port of the router on the roof. This is a simple, but highly effective way of rolling out IPv6. All the client needs to do is ensure that IPv6 is enabled on his device.
    I've highlighted two parts above, which is what he was getting at behind why switching off DHCP on my router is advisable. I don't know enough to counter any of that - but then again, I guess 'dummies' like me is the reason they do it. Maybe you might be able to comment on that - does this make sense?

    2.) Re Plex
    The ATV2 down the far end of the house, in our main bedroom, was really struggling with playing some of our files off the Plex server. The media is on a DAS connected to the Mini. Both the Mini and ATV2 were/are connecting via Wifi.

    I figured that a possible reason might be since the ATV2 was getting long in the tooth, it might be struggling with converting the media on device - although, AFAIK this is supposed to be done on the Server/Mini side?

    Regardless, I convinced the SO that if we upgrade to ATV4, these problems would be solved. So imagine how popular I was, after buying the ATV4, when they seemed to get worse!
    So whereas we scored Netflix and related apps on the ATV4, trying to play our existing media through Plex or Infuse, was simply terrible - to the point of even being worse that the ATV2! We now stream the same media through Netflix etc., rather than fetching that from the local - which is surely ridiculous!

    Someone suggested that if both the ATV4 pulling the media, and the DAS/Mini/Plex serving the media, are running through WiFi, I'm basically halving my Wifi throughput - so rather wire the Mini....

    The deadspots around the house (including the weak signal for the ATV4 in the bedroom) led me to start investigating the Ubiquiti Unifi APs as a possible solution - which led me to first getting the Mini hardwired - and left me with this mess! I cannot possibly go mesh until I manage to get my locals connected via LAN, since the APs will also need to...

    3.) Firmware and IPs.

    It is running the latest firmware - still in Beta mode (as explained in one of my earlier posts) - but the latest.

    I'm already being pushed just trying to get my head around the above - so nope, wouldn't have put it past me to get a basic like NOT allocating similar IPs to the same device! I'm not even sure where to go and check.

    I think the major spanner in the works, was me tinkering with OSX Server. Wish I had never gone down that road. [Will check in the Take Control Book what is was that I actually switched on - and pop something up below in a minute.]

    I'm pretty sure I've created a right-royal mess with that, which is potentially running the interference. I was about to pop something up in the Server sub-forum, to ask what the cleanest route would be to remove it, and restore everything to default.

    About two hours ago, I managed to get the Ethernet to stay connected, for all of 10 minutes, after messing around with switching things off [Open Directory??] over in Server. I couldn't connect to the internet, but at least the Ethernet preference setting wasn't jumping around like crazy.... and then - it started again. I think due to the Server software resetting something, and overriding my temporary IP settings in Preferences, to what I had specified in setting up that part inside Server.

    I am embarrassed by how nonsensical the above must sound to someone who actually knows what they are doing. I always thought of myself as being quite proficient around a PC/Mac - but goodness, this has brought me down to earth with a bump! Really appreciate the help!

    --- Post Merged, Jan 15, 2017 ---
    I've changed LAN cables, so doesn't appear to be that.
    Cannot say whether it ever worked properly before, since I never had a reason to wire something via LAN - had always managed with Wifi - and unfortunately, do not have a spare router lying around.

    That said, as mentioned above, I briefly had the ethernet working a while back for a few minutes, which increasingly points to the issue being with how things have been set up, rather than it being a hardware problem.
     
  24. jpietrzak8 macrumors 65816

    jpietrzak8

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    Dayton, Ohio
    #24
    Aha! Here's one item I've spotted:



    Yes, that would be bad! But, if I recall correctly, a "bridge" is a device does nothing more than receive IP packets and forwards them on. (I'm not sure bridges should ever do anything like NAT themselves, as that involves a lot of messing around inside the guts of packets...)

    But, you don't have a bridge. You've got a full blown router, which is mapping packets it receives on the 192.168.1.x network from the antenna, and placing them into the 192.168.0.x local network in your house. As this already requires the DSL-N55U to modify the contents of every packet it passes between 192.168.1.x and 192.168.0.x, there's really no reason it can't also do NAT at the same time.

    Another way to put it: the antenna is performing NAT on the 192.168.1.x range, and the DSL-N55U would be performing NAT on the 192.168.0.x range. So, it isn't actually a "double NAT" situation; it is single NAT performed on each of two different networks. Which is fine.

    If it isn't too massive of a pain, you might try to turn on DHCP on the DSL-N55U, and then switch the Mini and the ATV to use DHCP themselves. If this fixes the problem, then yeah, it was an issue somewhere involving static IP settings...
     
  25. Cassady thread starter macrumors 6502a

    Cassady

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    #25
    Ok. Many thanks - that was simple enough even for me to understand!

    Will switch DHCP "ON" in the router, and then take things from there. Will also try and get to the bottom of what I have been doing over in OS X Server, with that Open Directory... seeing IP addresses there, that make no sense.

    [EDIT:] Just thought I would mention, found the place under DHCP menu in the Router, that allows for Manual Assignment - "Manually Assigned IP around the DHCP List", which can be done via their MAC addresses...
     

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