Question on behavior of unmanaged switches with 'green' features

RouterOS Beginner Basics
1

How do i tell my Mikrotik router to keep the connection open when a “unmanaged” switch in some other part of the house doesn’t have anything plugged into it (besides maybe another dumb switch?) I have a bunch of these 5 or 8 port switches and previously it seems there were no issues when I used them as you would an ethernet wall jack, just plugging in when I needed to use a laptop, etc. (I often prefer a wired connection) But it seems my Rb741 doesn’t like that.

None of these dumb switches are connected to other routers or managed switches, but some of them are connected via other dumb switches. Is that a problem? If so it would explain a lot.

Also, as I said in the title, the newer ones are supposedly “green” meaning they have some kind of standby mode.

2

What exactly you mean by “keep the connection open”?

“Green” switch usually means that the switch can adjust power based on cable length (1m needs less than 100m). If there would be some kind od standby mode, then it should be the responsibility of switch to wake up from it when something starts to happen.

3

I guess what I mean is ‘reachability’ without it being dynamic and subject to the router’s autoconfiguration decisions.

I have several subnets containing various kinds of devices. Only one is connected to the default bridge, because of issues I’ve previously had with unwanted broadcast traffic. My goal is to have the separate subnets so I can implement Qos for the phones and also have a subnet for sensors and perhaps some CCTV video traffic. Which wont be connected to the Internet because it wont need to be.

Perhaps I should have run more cables, so I didn’t need to use switches like hubs in the rooms. Thats what I am doing and for the most part it works well. But sometimes it doesn’t and I still am figuring out why.

Each of the three non-WAN Ethernet ports on my Mikrotik is connected to at least one unmanaged switch. When there is a "server on that segment, for example, one is in the upstairs, and the traffic actually has to traverse two switches to get there, thats fine, its always pingable and reachable in around a microsecond, for a wired ping, everything is hunky dory, the route is kept open.

However, its not so for some of the other devices that are less active, or if a switch is on but has nothing plugged into it.

When I do use it, say by plugging in my laptop, setting its “location” to the appropriate subnet, it doesn’t work. I still have not configured it properly, so its always ‘reachable’.

When there is something like a IP phone or a NTP/DNS server plugged into a leg then the connection tends to stay open. But when there is not it seems I have problems with connectivity after a while.

Don’t get me wrong. I am still quite happy with my purchase. The issues that I have are minor ones which I suspect I would likely run into with most or all newer equipment, especially when getting it set up at the beginning. And I’m learning a lot of things I wouldn’t have been able to learn with other similar purchases in the ultra-low price range I chose.

I definitely am planning to step up to a gigabit-ethernet capable unit, probably fairly soon. Ideally I will just be able to port my config to it, directly.

4

I’m afraid that I don’t understand what you’re trying to describe. I’m used to switches, green or not, that do their work. Haven’t met any that would just doze off or something and had trouble waking up. :slight_smile: Maybe someone else experienced such thing and will be able to give you useful feedback.

5

I don’t think its the switches. I think it’s likely to be a mistake in configuration on my part, perhaps combined with the unfortunate situation of having two unmanaged switches between some machines and the Mikrotik instead of just one, and sometimes having some of the switches, which are meant to make several ethernet jacks available next to a table, etc, there and on with nothing connected to them.

Say you had switches and RJ45 jacks that went with them, integrated into your walls inside of electrical junction boxes, in every room.

Just so you would have a jack there you could plug into when you needed it.

None of the endpoint devices are ever going to be acting as a router to anywhere else. They will typically be laptops, and other gadgets which can use Ethernet in various ways. There may be two unmanaged switches between one of these endpoints and the Mikrotik. Thats the only aspect of it that seems unusual to me,

6

Layer2 switches are exactly that. There is no connection to them to keep open.

If you daisy chain 3 together one after another after another and connect a client device into that “far end” one then your router will likely have constant communications with the device hence traversing all 3 switches so that would effectively stop them from going into a sleep mode although I’m not totally sure that’s how a green switch actually works.

Aside from that you have the normal broadcast traffic on a network that should in theory also keep them awake but then again if that was the case, no switch could be “green” in the sense of going to sleep when left alone as it would receive the constant flow of broadcast but that also assumes it receives at a layer3 level not layer2.

I don’t think green is working exactly how you are envisioning it to.