Resolved Ethernet madness - make it stop

[jpietrzak8]

Appreciate the suggestions. I have emailed the ISP, and requested login codes for the airOs interface. Doubt they will give me access, but thought I would try my luck.

I am on the verge of ordering a new router with a dedicated ethernet "in"/WAN, and will pop something up here as soon as it arrives, and I have installed it. REALLY hopeful that the cause of all these issues lies with the old router!

Yeah, I've reached the point where even if my ISP provides me with a modem that includes routing capabilities, I always just plug my own personal ethernet router into it. That way, I don't care how they configure their modem/router, I simply ignore whatever they've done and just configure my own LAN the way I prefer. (This also allows me to switch from one ISP to another without having to make any changes to my local network.)

 

[organicCPU]

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.

Looking at the list of devices in the Router settings, most have now switched to DHCP. Those that are still listed as "static" are working, all those on DHCP are not connecting to the web.

I know it's been some days ago and I hope your setup is working now.
After rethinking, I had the idea that is probably not new to you and similar to one of your posts. What, if there were not 2 NATs on your net, but 2 DHCP servers in concurrency, even though you switched of DHCP on some device? One that gives you a connection (green light), one that takes you to nowhere (red light).
I don't know an elegant way to debug this, but to get on the right track you could try the following:
- launch your network preferences, so that you can see the red or the green dot
- turn on DHCP on your Mac in the network preferences
- launch the Terminal and enter:

ipconfig getpacket en0

Substitute "en0" with the actual interface you're using. If you're not sure which one it is, this command should give you an idea:

networksetup -listallhardwareports

As soon as you see a different color in your network preferences, try to repeat the first command by using the UP-Key and press enter or try scripting a loop.
If there is no output while having the red light, that means, that there is no (competing) DHCP server serving you an IP.
If you always get an output, I'd wonder, if the "router (ip_mult)"-value is changing or not.
I hope this'll help a bit to come closer to a solution and an answer, whether you've got two DHCP servers running on your net or not.

 

[Cassady]

I know it's been some days ago and I hope your setup is working now.
After rethinking, I had the idea that is probably not new to you and similar to one of your posts. What, if there were not 2 NATs on your net, but 2 DHCP servers in concurrency, even though you switched of DHCP on some device? One that gives you a connection (green light), one that takes you to nowhere (red light).
I don't know an elegant way to debug this, but to get on the right track you could try the following:
- launch your network preferences, so that you can see the red or the green dot
- turn on DHCP on your Mac in the network preferences
- launch the Terminal and enter:

ipconfig getpacket en0

Substitute "en0" with the actual interface you're using. If you're not sure which one it is, this command should give you an idea:

networksetup -listallhardwareports

As soon as you see a different color in your network preferences, try to repeat the first command by using the UP-Key and press enter or try scripting a loop.
If there is no output while having the red light, that means, that there is no (competing) DHCP server serving you an IP.
If you always get an output, I'd wonder, if the "router (ip_mult)"-value is changing or not.
I hope this'll help a bit to come closer to a solution and an answer, whether you've got two DHCP servers running on your net or not.

Will definitely give this a try. That could be behind things.

That said, my challenge lies in the speed at which the switching happens: on the Mini, it's barely a second, on the MBP a bit longer. But since I can repeat the function with using the UP-arrow(?) - thanks for that - looks feasible.

Hope to have the new router by next week, and will definitely report back.

 

[organicCPU]

That said, my challenge lies in the speed at which the switching happens

No problem! To avoid pressing the Up-arrow again and again, give that one liner a try:

for i in {1..5}; do echo "Test $i:"; ipconfig getpacket en0; sleep 1; done

Simply paste it to your Terminal window and press enter. Substitute "5" with the number of tests you want and "en0" with the right interface. If that's still too slowly, then delete "sleep 1;" that makes the script to take a rest for one second or assign a value of "0.5" or less. To quit a running loop press (CTRL + C). Good Luck!

 

[Cassady]

Very relieved to be able to close this loop and report that all is now sorted.

Still not sure where the issue lay fully, but since installing the new Router, and redoing the static IPs of all our devices, it's purring along nicely. Even the Mini connected 1st time via ethernet without any drama!

And the best news is that by giving my 2.4 & 5 channels separate Wifi SSIDs, I've managed to set things up so that the iPhones and iPads connect to the 5GHz connection, but when the device is too far away from the Router, it automatically switches over to the 2.4GHz Wifi seamlessly. The ATV4 down at the bottom is connected permanently to the 2.4GHz, and seems to be performing much better - and with the Plex media now connected via the DAS>Mac Mini>ethernet>router, no more issues with streaming our library!

The long and short of it is that whereas we will most likely still move over to a Ubiquiti Unifi AP mesh system eventually, things have improved to such an extent that we can wait and do so when all is convenient - which means I can gradually start buying a few of them to stock up the complete system, before making the switch-over.

A big thank you to the patient souls who took the time to walk me through possible issues! You have saved me countless hours of frustration!

 

[mellofello]

Turn DHCP back on and verify you can get a connection dynamically. That will insure you have no hardware issue.

Did you set a range of ips, on the router? If you type in the same Ip for whatever device you are typing on then it won't work.