After updating firmware it shows an error "Warning: CPU not running at default frequency" in the "System - RouterBOARD" window.
When I open the "Settings", there is a "716Mhz" frequency chosen, and if I select the AUTO, the error will disappear, what should I set there?

Auto

New default required settings since I don't know anymore which version ...

Alright, I will change this to all my Access points.

Also, I have a question about IP addresses, the problem is that before we used Kerio Control and now I want to remove Kerio and set up Mikrotik as the main router.
I have 57 access points (CAPS), and now MY MAIN question is how can I set up separate dhcp for AP and printers, and then I need to set up the second dhcp for more than 1000 clients (/22).

If you have multiple L2 broadcast domains (normally one L2 broadcast domain correlates with single IP subnet), then the task is easy: you have to set-up multiple DHCP servers, one per L2 interface (i.e. IP subnet) and things will be handled gracefully. However, if your L2 network is not segmented, then you'll have hard time to anything useful.

However, if your L2 network is not segmented, then you'll have hard time to anything useful.

Not necessary. It depends on the desired outcome
I.e. if you don't actually care about traffic between end nodes and you instead want more of a hub-and-spoke topology where everything can see the router, and the router can see everything else, but you don't want or care about L2 traffic going between any of the spokes. Then you can just throw everything (even different VLAN's) into a single bridge with horizon set to the same value, then you only need 1x subnet, DHCP server etc to handle everything

I've done this plenty of times, particularly in hotels, universities etc. Every switch port has isolation and DHCP snooping enabled except for the one facing upstream towards the router
Dramatically simplifies deployment and is still secure, no traffic goes between rooms/switch ports. Lot easier than creating 1000x VLAN's/subnets/DHCP servers/firewall rules for 1000x switch ports......
And if you do want unicast L2 traffic between spokes you can use local-proxy-arp on the router. All traffic then logically needs to flow up to the router, and the router will then forward it to the destination

However, if your L2 network is not segmented, then you'll have hard time to anything useful.

Not necessary. It depends on the desired outcome

My answer was given strictly in context of having multiple DHCP servers serving different clients ... inside same L2 network. And the setup you explained is not exactly trivila, IMO it falls into "hard time" for people asking such questions here.

As I said before I'm new in Mikrotik, I will read a little about your answers and then will write: |

I need assistance in selecting AP and PoE switches. We're planning to purchase 15 additional Mikrotik access points this year, and we already have 8-10 APs on each floor. I think we'll need PoE switches to support them. Can you help me choose the right ones?

I guess your choice is between these two, depending on the number of ports you need:
8 ports:
CSS610-8P-2S+IN
24 port:
CRS328-24P-4S+RM

1) Also, in some classrooms, we have 30 devices. Is one AP enough, or should we install 2 AP's in one classroom?
2) Will they interfere with each other if I place 5 in the corridor and also inside the classes?

1- depends on how much data each of the clients will send/receive over wifi. But about 30 clients is advised as limit per AP (don't know anymore where I read it). So you're at the border there. Start with one, foresee cabling if needed for second one.
2- if you do your network planning carefully avoiding stupid wide channels and making sure there is no overlap (BOTH on 2.4 and 5GHz), this should be perfectly possible.

1) Last school year we had a lot of problem with wi-fi's, so I think it will be good to install two access points in one classroom, where we have a lot of devices.
2) Could you please assist me in configuring wide channels correctly?

2) Could you please assist me in configuring wide channels correctly?

Generally narrower channels give better stability at the cost of reduced top speed. In 2.4GHz band it's crucial to use only 20MHz wide channels and possibly stick to using channels 1, 6 and 11 (or, if it's legal to use channel 13 in your country, channels 1, 5, 9 and 13). Anyway check for interference from outside, you may be constrained to not using some of channels due to external interference. In 5GHz band number of channels is greater, so it's generally possible to use 40MHz channels ... or even 80MHz channels if the walls between adjacent rooms attenuate signals well enough.

Generally, channel width (and channel frequencies) is configured under /interface/wifi/channel (profiles) by setting width property to either "20mhz" or "20/40mhz" ... or by setting channel.width property of wifi interface directly.

Anyway check for interference from outside, you may be constrained to not using some of channels due to external interference.

1) Can you please inform me of the proper way to check this?
2) My country is not listed, so I selected the United States. Is that okay, or should I select no_country_set?
3) I tried to set up as you instructed (about 5G I'm still wrote only 5180) ( Please review and let me know if any changes are needed. (I'm using CAPsMAN on MikroTik).

When configuring channel widths, don't use "40MHz turbo", it's a not-so-widely-supported wireless layout. To be as compatible with clients as it gets, always use 20MHz as "control channel width" setting. If you want to provide wider channels (in reality they are multiple of control channel width), set "extension channel" property to e.g. Ce (or XX) for 40MHz or Ceee (or XXXX) for 80MHz. The difference between different extension channel layouts is placement of control channel inside the "channel bundle" ... it seems that the most widely supported layout is the one with Control Channel at lower edge (i.e. Ce or Ceee). Setting it to XX (or XXXX) means that it's up to CAP to decide the layout (in principle it's fine as well, but it may select something other than Ce(ee) and as mentioned, some clients might not like it).


In modern (wifi) capsman, channel settings are organized a tad differently. The new wifi doesn't support anything but standard 20MHz channel widths, so the channel layout is overloaded into "width" property (you can select e.g. "20mhz" or "20/40mhz" of "20/40mhz-Ce"). Which actually makes it more clear that "wide" channels are composed of multiple 20MHz channels.


Checking external interference: while ROS provides a few tools, it's quite handy to use smart phone with a scanning app installed (I use "Wifi Analyzer" but there are others). Use it close to your AP (but turn off AP while doing the interference scan to avoid AP to overload phone's receiver which would then show much less interferers).

I guess proper thing would be to set country to something. united_states might not be entirely correct for your country, specially in 5GHz band different countries impose different restrictions and it is possible that regulatory agency may chase you down for not adhering to regulations (e.g. using too high Tx power ... not very likely if you'll be using your AP indoors ... or using frequencies not allowed in your country or not adhering to DFS rules which vary from country to country as well).

I used for 2.4 and 5GHz bands 20MHz as a "control channel width" in the setting.
Really, I don't think I need wide channels because there are access points in every classroom and also in the halls. (But I did as you wrote, please look again, and let me know if something still needs to change). Regarding the country, I couldn't find mine on the list, so I chose a neighboring country. Is that okay?

2) Could you please assist me in configuring wide channels correctly?

Generally narrower channels give better stability at the cost of reduced top speed. In 2.4GHz band it's crucial to use only 20MHz wide channels and possibly stick to using channels 1, 6 and 11 (or, if it's legal to use channel 13 in your country, channels 1, 5, 9 and 13). Anyway check for interference from outside, you may be constrained to not using some of channels due to external interference. In 5GHz band number of channels is greater, so it's generally possible to use 40MHz channels ... or even 80MHz channels if the walls between adjacent rooms attenuate signals well enough.

Generally, channel width (and channel frequencies) is configured under /interface/wifi/channel (profiles) by setting width property to either "20mhz" or "20/40mhz" ... or by setting channel.width property of wifi interface directly.

It seems like my device doesn't have just 40MHz; there is only with a turbo. (I have the last firmware update 7.13.3).

I used for 2.4 and 5GHz bands 20MHz as a "control channel width" in the setting.

That's fine. And the Extension Channel setting makes both 2.4GHz and 5GHz radio to work with 20 and 40MHz wide channels. I suggest you not to do it on 2.4GHz radio.

Regarding the country, I couldn't find mine on the list, so I chose a neighboring country. Is that okay?

Most probably it's fine (specially so if your country shared common history with Uzbekistan before 1990 which would make higher probability for similar country regulatiobs regarding radio frequencies).

I used for 2.4 and 5GHz bands 20MHz as a "control channel width" in the setting.

That's fine. And the Extension Channel setting makes both 2.4GHz and 5GHz radio to work with 20 and 40MHz wide channels. I suggest you not to do it on 2.4GHz radio.

Regarding the country, I couldn't find mine on the list, so I chose a neighboring country. Is that okay?

Most probably it's fine (specially so if your country shared common history with Uzbekistan before 1990 which would make higher probability for similar country regulatiobs regarding radio frequencies).

There are a few more things:
1) After changing some settings, my 5G wifi is not showing up on all devices. For the devices that can see it, the connection is lost every 20-30 seconds.
2) We bought 10 more CAP AX access points. I'm trying to connect them to my Capsman, but it's not working. I tried to download the wifiwave2 package for my router (CCR1036-8G-2S+), but I couldn't find it.
3) Is there a way to force an update of my router firmware? The official website says version 7.15.3 is available, but my router (still showing 7.13.3) won't update. I've downloaded the package and copied it to the Files folder, but it still doesn't update after restarting.