Connecting 2 access points via ethernet

[chains007]

Hi Everyone,

I searched the forums but couldn't find the exact situation i'm trying to solve for.   I have a Nest wifi setup with 1 router + 4 access points (3 of which are actually Nest routers...1 is a point).

I get a great connection for 3 of my AP's....the 4th by necessity is in my TV cabinet, and consistently gets a weaker signal.

I can't realistically run ethernet from my main router to the weak AP.....but I do have an existing ethernet cable (from the previous owner) that runs from one of my strong APs (hardware is the Nest router) to the weak AP (another Nest router). 

My question is - is it possible to connect just two AP's together via ethernet so the weak AP gets the benefit of the strong signal from the other AP (since both have ports since they are routers)?  There is no other hardwiring in my network that is possible from the main router.  Does what I propose make sense to do at all and is it possible?  If so, which ports on which AP do I connect the ethernet cable to for this to work?  NOTE: I do have switches at both AP's to expand the ports since I have equipment at both locations that I have plugged in.

Thanks!

[MichaelP]

Hello @chains007 

Unfortunately, for somewhat esoteric reasons, connecting two wireless secondary access points to each other via Ethernet does not work in the way you might hope or expect.

The 802.11s mesh only runs over the WiFi interface, and part of what it does is discover multiple possible paths through the mesh and select a path with the fewest hops without introducing traffic loops through those redundant paths.

When you connect a node via Ethernet, it creates another path, but it's not a path the mesh protocol can see directly. So, the units rely on an older protocol (802.1d Spanning Tree Protocol) to detect the extra path. But, to eliminate the traffic loop that would then occur, 802.1d then disables the mesh interface on one of those two access points. You want it to disable the mesh interface on the one with the weakest mesh connection, but 802.1d doesn't know about that. So, it's going to be essentially random which one gets disabled, and if it's the closer of the two, the result will be extremely poor performance for both of those units (and all of their clients).

Long story short, I don't recommend this. If you can find a way to get an Ethernet connection from the primary to that secondary, you'll be much happier with the result. Note that if you have coaxial cabling in place, a pair of MoCa adapters can turn it into an Ethernet equivalent without impacting most of the things that cable may already be used for.

[chains007]

Hi @MichaelP 

Thanks for the reply and info.  This is very helpful.  I definitely want to pursue your suggestion to use a pair of MoCa adapters since i do have a coax port hear the AP that is weak .  How would I actually do this?

My current setup is:

Coax -> Modem -> (ethernet cable)-> Nest Router...then wireless to all my APs.

From my understanding, the MoCa adapter converts the coax port in my wall into an ethernet jack.  So how would i actually use one at the main router (since the modem is there already)?  Or maybe I don't use one there at all and just install one on the coax port near the AP i'm trying to hardwire?

Thanks!

[MichaelP]

I will do my best to summarize, but you'll want to study the MoCa adapter instructions thoroughly as well. Here's an example: https://arris.secure.force.com/consumers/articles/General_FAQs/SBM1000-Installation-with-a-Cable-Mod... 

To understand what's going on here, think of the coaxial cable as being sort of like the air with radio frequency going through it, separated into different channels that can coexist without interfering with each other. MoCa uses a part of the spectrum on that cable that isn't already being used for internet service or cable TV channels. So, the topology looks a little strange, because the coaxial cable is going to feed your cable modem (and any set-top boxes), but it's also going to connect to your MoCa adapters, one of which will be fed from the inside of your Nest WiFi Router (it's LAN Ethernet port, directly or via a switch). This will create a MoCa network that is part of the "inner" network created by your Nest WiFi Router, but on a different set of "channels" on the coaxial cable than the part that are feeding your cable modem. So, it looks sort of like a "loop", but really isn't because of the different channels being used.

So, let me try to summarize the connections:

• Coax from internet service provider feeds all of the coaxial jacks in the house (make sure any unused jacks have terminators on them, by the way).
• One of those jacks that currently just feeds the cable modem will need a new splitter connected, to make two coaxial connections in that area.
• One branch from that splitter will go to the cable modem, but that branch will also include a MoCa filter (which should come with the MoCa adapters). This will "hide" some of the MoCa energy from the cable modem.
• The other branch from that splitter will go to the first MoCa adapter. You now have a MoCa network, but it's not yet connected to your "inner" local area network.
• The cable modem should already be connected via Ethernet to your primary Nest WiFi Router.
• The Nest WiFi Router's LAN Ethernet port now needs to be connected to the Ethernet jack on the MoCa adapter. This now connects your MoCa network to your "inner" local area network created by the Nest WiFi Router.
• In another area of the home, you'll connect the other MoCa adapter to the coaxial network. You may need a splitter there if something else is already using that coaxial jack.
• You can then connect a secondary Nest WiFi Router (one that's already working as a mesh secondary, but presumably has a weak connection) to that MoCa adapter via Ethernet. It should quickly switch to using that connection to carry traffic back to the primary instead of using the 5GHz mesh WiFi.

Hopefully this makes sense. When doing something like this, draw some pictures to get it clear in your mind. Then take it step by step and test in between each step. Frequent testing lets you know when one of those steps hasn't worked quite right for some reason instead of doing it all and wondering why it doesn't work at the end. Good luck!

[chains007]

@MichaelP - awesome, thanks for explaining the setup. 

One minor clarification needed: for the secondary Nest Wifi Router that's working as a mesh secondary - do I connect to the MoCa adapter to its WAN port or LAN port?  (i'm guessing WAN?). Thanks! 

[MichaelP]

Either port should work. But, I would pick one and be consistent about using it. The easiest way to do that is to use the WAN port every time.

[chains007]

Got it.  If i'm using a switch at that access point (similar to what I'm doing now), that switch should definitely connect to the LAN port on the router correct? 

Thanks again!

[MichaelP]

I don't think I'd do it quite like that. If you're wiring up that secondary, you want it to be a leaf node on the wired network, not feeding more wired devices downstream. So, if you have a MoCa adapter that includes multiple Ethernet ports (like the example from Arris), you can plug the secondary Nest WiFi Router into one of them and other wired devices (including a switch if you need even more ports) into the other ports. This should leave the other port on the Nest WiFi Router empty. The reason for this is because those two ports are connected to each other only through a software (virtual) bridge (switch), and any traffic between them has to be copied back and forth by the Nest WiFi Router's processor (compared to a hardware switch that can do that more directly).

Edit to add: If your remote MoCa adapter only has a single Ethernet port, use that to feed an Ethernet switch, and then hang your Nest WiFi Router and other wired devices off of that.

[Jeff]

Hi, chains007.
I just wanted to jump in real fast to see if you saw MichaelP's reply and to see if you still needed some help on this or if you were able to get it sorted out. If you are still needing some help, just let us know and we'll be happy to continue helping.
Thanks.

[Jeff]

Hi, everyone.
As we haven't had any activity here recently I'm going to go ahead and close the thread. If you have more to add, feel free to start a new discussion.
Thanks