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tspascoal
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CAps configuration

Sun Sep 19, 2021 5:45 pm

Hi,

I'm going to do an install on a house with a medium dimension (single floor, 10 divisions)

I'm going to wire all divisions so that is not the issue, but I (also) want to install wireless that covers the entire house.

I've already bought a Cap AC (just before the CAP XL damn) to test coverage and speeds to estimate how many I will need (probably between 2-4, maybe a wap AC in the mix (there is a central place in the building that is outside and should be a good spot to cover a big part of the house) [since all divisions will be wired I will be able to move AP around or add more as needed, so I don't need to get it right at wiring time]

The CAPs will be powered with POE

My question is not about the coverage, but about the best configuration for the CAPs.

I may use capsman or not

What is most advisable:
  • Configure in router mode with different IP DHCP ranges per device (does capsman even allow this?)
  • Configure in router mode with DHCP being handled by (main) the router to avoid clashes (have never understood if routing tables are updated if you move between APs and keep the same IP)
  • Configure in bridge mode so there is a single IP subnet for everything

regarding SSIS:
What is best, configure different SSDIs for 2.4 and 5 Ghz (and let users figure one which they want to connect to) or use the same SSID for both frequencies and let devices handle.

Thank you
 
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mkx
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Re: CAps configuration

Sun Sep 19, 2021 6:33 pm

First thing you have to decide is whether all APs form single large network or each runs their own.

If each runs their own, then they'll run in routing mode, but roaming won't work (not nicely that is), so in this case you better set them with different SSIDs. CAPsMAN is out of question in this case.

If you want them to make one big network with clients roaming between APs, then you'll have to run them as simple APs (in this case CAPsMAN is feasible) in single L2 network (no routing). Single L2 network also means single DHCP server for all APs (you won't know which AP client connects to from its IP address... when using CAPsMAN you can check central registration table to get this information).

As to the 2.4GHz vs 5GHz distinction: if you expect most clients to support 5GHz and you'll plan for complete 5GHz coverage, then you can set same SSID on both frequency bands. Then you reduce Tx power for 2.4GHz transmitters so that signal strength measured by clients is slightly lower (or equal at most) as 5GHz signal. This way dual-band clients will select 5GHz AP most of the time while they'll still roam to 2.4GHz if needed (e.g. behind the third concrete wall), you also won't have to manage two sets of security settings.
 
tspascoal
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Re: CAps configuration

Sun Sep 19, 2021 7:17 pm

First thing you have to decide is whether all APs form single large network or each runs their own.

If each runs their own, then they'll run in routing mode, but roaming won't work (not nicely that is), so in this case you better set them with different SSIDs. CAPsMAN is out of question in this case.

If you want them to make one big network with clients roaming between APs, then you'll have to run them as simple APs (in this case CAPsMAN is feasible) in single L2 network (no routing). Single L2 network also means single DHCP server for all APs (you won't know which AP client connects to from its IP address... when using CAPsMAN you can check central registration table to get this information).

To be honest, it's not really important if it's one big network or not. Device isolation (per AP) would be nice but not important

Roaming is more important, so big network it is. :) (I could setup vlans if it mattered that much I guess)

In my own house I have 3 APs (a AC3 in non routing mode and a powerline devolo AP. My main router (RB951G-2HnD) is also providing wireless connectivity (with a different IP ranges pool) and it roams just fine (i set it up like that because I thought it would roam better. Funny how things go).

Curious how do you say multiple networks don't roam nicely?

As to the 2.4GHz vs 5GHz distinction: if you expect most clients to support 5GHz and you'll plan for complete 5GHz coverage, then you can set same SSID on both frequency bands. Then you reduce Tx power for 2.4GHz transmitters so that signal strength measured by clients is slightly lower (or equal at most) as 5GHz signal. This way dual-band clients will select 5GHz AP most of the time while they'll still roam to 2.4GHz if needed (e.g. behind the third concrete wall), you also won't have to manage two sets of security settings.

Clients will support both frequencies, but it's unlikely I will have 5G coverage, that is why I asked if it made sense to have the same SSID so clients would (automatically) switch between 5G and 2.4G if they went too far and 5G coverage isn't enough (users are not savvy and would complain if they have to switch between SSIDs as they move around the house)

I will have to try it out and will keep in mind lowering the tx power of 2.4 tip

Thank you
 
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mkx
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Re: CAps configuration

Sun Sep 19, 2021 7:50 pm

Curious how do you say multiple networks don't roam nicely?

When client decides that current BSSID (AP running certain SSID) signal is not good enough, it looks around for another feasible AP. If it finds another AP running same SSID, it will roam which means it'll expect all the IP settings to remain valid (gateway's IP and MAC address, ...) and will not re-start the DHCP lease process. If things are set up right, then the network outage will be really short, lost will be only frames already buffered at old AP. If things are not exactly the same, then client may have to perform a few tasks. E.g. if gateway IP address is the same, but MAC address changed, then client will not be able to transmit data outside own subnet until cached ARP entry times out and it learns ne MAC address. If things go real bad, it'll have to re-do DHCP procedure and in that case it might get a different IP address because it'll talk to different DHCP server. Either way, connectivity outage will be much longer and it will probably disturb user's experience much more.

If client decides to use different SSID, it is assuming it'll be different network and always performs full network access procedure (e.g. starting DHCP procedure without delay). It takes some time and drops all active connections. IMO this is not roaming, but attaching, to another network.

When client is idle, all procedures hapoen quickly enough not to be obtrusive.
 
gotsprings
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Re: CAps configuration

Mon Sep 20, 2021 1:03 am

Having an ACL in caps to boot things below -87 RSSI has really helped in the installs that I can't get off caps-man.

The throughput and inability to deal with interference is the Hallmark of Mikrotik WiFi. But kicking devices off an AP before the signal goes absolutely to crap... Has made clients "roam" a little sooner. Making the systems considerably more stable. Lessening the customer bitching.

Changing wifi vendors was the silver bullet.

I love caps-man in concept. But the radios it controls just are not up to the level of WAPs we have used for 6 years now.

Or as I pointed out really painfully to sales.
"We moved from the Rx00 series to the Rx10 series in 2016. That series has finally been put in "end of sale", In 2021. So we have to move into WiFi6 at this point. The current Mikrotik WAPs are closer in abilities to the Rx00 series, lacking the features and compatibility put in place in the Rx10 series. Or to keep it simple... It's closer to the WAPs we had in 2014... Without the cool antennas and beamforming."
 
tspascoal
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Re: CAps configuration

Mon Sep 20, 2021 12:33 pm

Curious how do you say multiple networks don't roam nicely?

When client decides that current BSSID (AP running certain SSID) signal is not good enough, it looks around for another feasible AP. If it finds another AP running same SSID, it will roam which means it'll expect all the IP settings to remain valid (gateway's IP and MAC address, ...) and will not re-start the DHCP lease process. If things are set up right, then the network outage will be really short, lost will be only frames already buffered at old AP. If things are not exactly the same, then client may have to perform a few tasks. E.g. if gateway IP address is the same, but MAC address changed, then client will not be able to transmit data outside own subnet until cached ARP entry times out and it learns ne MAC address. If things go real bad, it'll have to re-do DHCP procedure and in that case it might get a different IP address because it'll talk to different DHCP server. Either way, connectivity outage will be much longer and it will probably disturb user's experience much more.

If client decides to use different SSID, it is assuming it'll be different network and always performs full network access procedure (e.g. starting DHCP procedure without delay). It takes some time and drops all active connections. IMO this is not roaming, but attaching, to another network.

When client is idle, all procedures hapoen quickly enough not to be obtrusive.
Thanks for the detailed explanation.

It currently is not that bad.

Maybe i will try a single pool, but that could mess with my IoTs....
 
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mkx
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Re: CAps configuration

Mon Sep 20, 2021 12:59 pm

Maybe i will try a single pool, but that could mess with my IoTs....

What people mostly do is to have multiple wireless networks with different SSIDs and using different VLANs on wired backbone. Then each of networks has it's own IP subnet.
Those wireless networks actually share same wireless infrastructure, all but one SSID are "virtual" or "slave". All APs are configured the same way so that member of any wireless network can roam freely. Unless of course you want to constrain some wireless network to only a few APs.

Actually possibilities are numerous and it's hard to say how to proceed without knowing what exactly are your wishes and needs.

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