That makes things more complicated, and does not solve the issue: clients will not switch to another AP just because they cannot get a DHCP response.
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Well, then that's a problem with the phone if it's not roaming when it should be.
As has already been mentioned before, the client device is the one that makes the decision to move to a different AP.
If you forcefully deauth a device, it will take much longer to reconnect to another AP, if it even reconnects at all. There's a good chance you'll trigger the network to be marked as unusable which will mean that the Android device NEVER reconnects without user intervention.
sure but practically speaking no one has control over their phones roaming code... and the poor sysad who stuffs it up gets a thousand students complaining.
@rakesh can you move the APs so they are about equally far from the entrance?
also what AP are you using? maybe just replace them with something more configurable
Primary reason is that captive portal which is running on the OpenWRT router and APs must work as APs(i.e. dumb).
IMHO you should set wpa2-psk, aes, 40mhz channel width, and low xmit power
what are options for mode? can you set n/ac and drop a?
also I would suggest to manually choose channels, set the two APs to different non overlapping channels at 40Mhz you can look at Wikipedia for list of channels
if low power isn't working try medium, always try to find lowest power that works.
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I had the same problem with 2 Ubiquity AC-lite trying to cover as much floorspace as I could in my 2 floor house. Unfortunately the location of the access points was more or less fixed and I could not install them far from each other. With default settings in regards of transmit power, minimum RSSI, cell size tuning etc it was a mess. Clients were not roaming and signals from both APs were overlapping a lot.
It took me a lot of experimenting with all those options and scanning with the phone around the house to achieve the correct settings so that clients roam when they change floor and prefer the AP of the same floor all of the time.
Having the APs in the same room can be more tricky but not impossible. It just requires some effort from your side to test the range of each AP in the room and find the correct tx power, minimum RSSI, minimum allowed speed etc for correct distribution of clients among the APs.
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Well, but people can. It's a way to make people change to another AP.
Yeah, but almost any of the approaches here will lead to even more complaints because anything that attempts to force a client to roam is going to create losses of connectivity and/or the network being blacklisted to the point where the user has to intervene.
that isn't my experience at all. most devices come out of the box blasting full power. the signal is super strong so phones don't roam, but this means the one AP is way too congested. service is crap. cutting power means phones roam and everything works better.
obviously don't cut power so much that there are big dead spots, but most APs don't even let you do that much power cutting. here we have low, medium, high... start at low
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Not full power. Actually maximum allowed power change for a region to another. Default transmission power is usually considerably less than hardware maximum.
that's what I meant by full power, full allowable.
No, I don't think they even set it to the maximum allowable. High power increases the temperature of the router which would affect the lifetime of the router. But anyway, I guess he will have to check the coverage of each AP using a WiFi scanner and work on reducing overlaps.
technically the min(max allowable, max possible)....
As here, for example, see above in screenshot where under "Transmit Power:" it show "low, middle, high" and high is selected... I've never seen a factory firmware that does anything other than selecting max out of the box... perhaps the higher end ciscos have some useful "auto" function, but even "auto" probably just means "max" for most firmwares.
Cutting power is fine, that's the right way to do it and SOP when setting up any sort of multi-cell radio system.
Forcefully deauthing or refusing to give a DHCP lease as has been discussed here is a whole other story.
And I am fairly certain both Cisco and Ubiquiti's UniFi enterprise APs do the sort of automatic power control mentioned by another user. I know I've seen UBNT reference it in marketing material.
sure, Cisco and ubnt are likely to do better.
forcefully deauthing on received signal strength reportedly works well, APs are often much louder than the phones they serve so they are able to figure out when to drop a client better than the client can figure out to roam... but DHCP is a big hack, I agree it isn't the right approach
- Limit by DHCP
- Limit by Max Associations in Wireless.
Is the end effect different on client?
Will the client try to reconnect to a different AP?
Association happens long before DHCP, and there is a matching de-association event. Of those two options, I would prefer association-based for those reasons.
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Someone raised a point here that once a client is denied DHCP it will give up retrying connection to same SSID.
I am trying to understand if in the case of Max Associations, client retries (to the same SSID) and eventually he connects to another AP.
Generally yes, I believe.
Also, if you try to limit by DHCP you have several other problems;
- IPV6
- need a separate network segment
- will break existing connections
- some devices may just keep trying and trying...