Nest Wifi Pro wired backhaul, ethernet port on a point

[nibi]

Hi there,

I have a Nest Wifi Pro 3-pack set up with a wired backhaul using an unmanaged switch. I am very happy with the performance of my network and there are no issues whatsoever.

Recently I have bought a new device which I would like to connect to my network using an ethernet cable. However, I have run out of ethernet ports on my 5-port switch and was wondering if I can use the ethernet port on one of the Nest Wifi Pro points. I have heard that on child nodes both ports (WAN and LAN) act as LAN so I just don't want the new device to somehow have an impact on the performance of that node's wired backhaul.

Will this have any impact on my wired backhaul?

[MichaelP]

Hello @nibi 

You can connect a device to the other port on a wired secondary Nest WiFi Pro. Just keep in mind those two ports are bridged in software running on that secondary, unlike the ports in a dedicated Ethernet switch. So, any traffic to/from the new device will be adding some extra load to that device. However, this isn't any different from how traffic to/from WiFi devices connected to that secondary is handled.

Personally, though, I like having secondaries like this be connected to the switched Ethernet network without relying on them to bridge anything else unnecessary. In your case, you could accomplish this by purchasing another inexpensive (unmanaged) 5-port Ethernet switch and connecting it at the end of the run that currently goes to that secondary Nest WiFi Pro, then connecting the secondary and any other nearby devices to that switch. This style of core + leaf switch structure is pretty common, and works quite well. I currently have a structure like this and have used it for at least 5 years.

[nibi]

Hi @MichaelP 

Thanks for the insights.

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@MichaelP wrote:

Just keep in mind those two ports are bridged in software running on that secondary, unlike the ports in a dedicated Ethernet switch... However, this isn't any different from how traffic to/from WiFi devices connected to that secondary is handled.

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So connecting this new device via ethernet will be exactly the same as connecting via WiFi? In that case I'll just go ahead and connect the ethernet cable.

The only reason I got confused is because I know very little about networking and my thought process was that if a child node/point doesn't have WAN and treats both ports as LAN then it might broadcast WAN traffic to this new ethernet/lan device as well, thereby affecting the performance of the wired backhaul. Obviously this is just conjecture and it seems to me that you are saying that won't be the case.

[MichaelP · Accepted solution]

Yeah, the port is bridged just like the WiFi interfaces are. So, it will work. It's just slightly more overhead. The "bridge" function (and an Ethernet switch is just a multi-port bridge) learns which devices are reachable from each port, and filters traffic out so it only goes where it needs to. So, no, the device you connect to the spare Ethernet port won't see any traffic to or from any other devices.

[nibi]

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@MichaelP wrote:

Yeah, the port is bridged just like the WiFi interfaces are. So, it will work. It's just slightly more overhead.

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Thank you so much for bearing with me, really appreciate the explanation. Just for clarity, you mean slightly more overhead compared to wifi or a dedicated switch?

[MichaelP]

Slightly more overhead than using a dedicated switch in that position with your secondary Nest WiFi Pro and new device both connected to it. The reason is just down to that bridging being done in software running on the secondary Nest WiFi Pro unit's processor instead of dedicated hardware inside an Ethernet switch. So, it adds a few milliseconds of latency to every packet. But, wiring either way will be much lower overhead than connecting via WiFi.