I put a question mark in there because I honestly don’t know if this is a Mikrotik issue or not. I have a hex that I have put into service recently in my home; small home network only, only a few devices.
I have a few devices and they are all working fine except for one. I have an old cheap tablet that I only use to receive push notifications from an security system. This tablet has no cellular and is wifi only.
On my old router this worked fine, no problems. Once I took the old router out and put the new mikrotik in the problem began. If I put the old router back in the problem goes away. Mikrotik back in and problem returns. I have changed no settings on the tablet and it is too old to receive any updates so the tablet should not have changed at all, leading to me to believe that the router must be the reason.
So here’s the problem: The wifi on the tablet seems to “go to sleep” for some reason if I don’t use it for a few hours. I pick it up and turn the screen on I see the wifi logo come on as if it was off. The way it is supposed to work is that if my security system has an alert it sends a push notification to the tablet via wifi which makes a notification sound and I check the tablet to see what it is. But now the system sends the push but the tablet does nothing. So I pick it up and turn the screen on and then I see the wifi logo come on and then I get the push.
So, at first, I could not think of how the router could possible be responsible for this issue. I checked the tablet every way I could and came up with nothing. I reset the tablet to factory and same thing. I checked all the power saving settings and nothing. Then, grasping for anything, I changed back to the old router and it worked fine. How?
I do not use the router to control my wifi. I have a separate WAP that I use for wifi and it is the same and has the same settings regardless of old or new router so that should not be the issue.
I tried changing the lease settings on the router and that did nothing.
I tried making the IP address static - also nothing.
I tried making the IP address manually assigned - nothing.
So at this point I am at a loss. Why would the wifi go to sleep with the mikrotik but not with the old router?
These sorts of devices, especially older ones, tend to behave with certain idiosyncrasies. Disconnecting from wifi after a period of inactivity is a sort of typical one. This may take some time to troubleshoot
One of the things that comes to mind: when a DHCP lease is handed out, it is “valid” for lease-time length. At half of this time, the device attempts to renew the lease - leading to wifi activity. Older devices and off-the-shelf routers sometimes have short lease-times like 5m, which prevents wifi from going to sleep. Mikrotiks lately use (I think) 1h. This difference can lead to your observed behavior.
Change your dhcp server lease time to 5m to test, and disconnect-reconnect the device to see if this is the case.
Again, this is only a guess. Even if true, it’s not really all that recommended to use short lease times… But as a test it doesn’t hurt.
The old router was a Zyxel USG40. The configuration of that router is rather lengthy to describe here because it uses a different operating system but it is set up similarly to the hex.
The hex is a old hex, not the refresh.
Network diagram? The internet comes in through a cable into the cable modem and then to the hex. The WAP is plugged into the hex and the tablet gets its connectivity through that.
I did try adjusting the lease times but only by making them longer. I never thought that making it shorter might actually be better. I will try that, thank you lurker888. Right now I have it manual static IP.
Static dhcp ip is still dynamic It’s just that it “randomly” always assigns the same address.
EDIT: So static manual. Wasn’t too long; didn’t read. You could run a periodic (every 1m) ping to it to see if this is the problem. Otherwise move on, again: just an idea.
Looks like setting the lease time for that singular item to 5 minutes “appears” to have fixed the issue. Has not fallen asleep in 24 hrs. Thank you for that idea. I was doing the exact opposite and making the lease 12hrs or 1 day thinking that was the problem and of course that did not work.
I’m guessing that the Zyxel had short leases or handled it some other way. It was transparent to me so I have no idea how it handled it.
All that said, is there any danger or potential issue with leaving this singular item to having a lease time of 5 minutes? I hope not since it seems to have fixed my issue.
If you set it only for the singular item and it solved your problem, just leave it. You could play around and test at what point the failure sets in, but it’s mostly pointless.
If you only set the lease time for the specific item, the effects will only apply to the one device. My caution was only with regard to running the entire dhcp server with a short lease time - this was quite common 5-10 years ago, but now longer times are generally recommended, in line with Mikrotik current defaults.
