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AC2600 and DHCP management
Hi everybody.
I have extended a wifi network in a school, and i have used for that, 4 AC2600, in AP mode, and the modem/router is managing the DHCP.
Everything work fine while there is not to...
PatDen wrote:
Not with simply routers i présume.. ?????Correct. These are generally dedicated SERVERS with many ISP lines coming into them depending on requirements. Think of them as large modems that do DHCP. They are fed by wireless access point/repeaters located in various places.
Coffee shops and other local retail places might use a single router depending on the size of the store, as they might assume less than 250 devices connecting at the same time, but they would more then likely have better routers than your standard run of the mill Residential models. ISP speeds would also likely be higher as well.
The basic problem will always be the number of users at one time and the available bandwidth.
What good do you think changing the lease time would be?
Lease time determines when the device would ask for an IP Address. Generally this would be 1/2 the time of the lease. It could be longer, but not by much depending on the load of the device. Say it is set for 24 hours (usual default). At 12 hours the device requests a new lease. Almost ALL the times it will get the same IP Address for 24 hours. If you make the lease 2 hours, then the request comes in at 1 hour and a new 2 hour lease is given. OK, that does set the release of the IP Address to 2 hours IF no new RENEW request has come in and it is returned to the pool.
Good it you want to do that. However there is ONE assumption that you don't know the answer of? The question is DOES the DHCP server/Router manage the pool in such a way that it knows which IP Address as the oldest inactive one to use the address? If it did, the oldest one that didn't use the IP Address, that address would be dropped for that user and given to a new user asking for an IP Address (based on MAC Address of the user).
So the real question IS how many IP Addresses would be used at the SAME TIME. That is NOT the same as CONNECTED at the same time. Now once you had that, could you tell HOW LONG they needed the IP Address?
What I mean is you'll have 180 users at most active for 3 hours. Great, you could set the least time to 7 hours and you'd be all set. Now say the answer is 220 users active for 1/2 hour. That could be a problem. First you are approaching the limit of available IP Addresses at any one time (254) and the shortness of the lease time.
On top of that you really don't know what the router does after it exhausts the DHCP pool. Does it reject all new connection attampts? Does it tell the user why? Does it knock someone who is inactive off?
What you might require is a far more complex system to handle something for possibly the number of ALL users you could expect.
It feels to me like this is begging for a solution based on equipment toward the commerical grade. It sounds like things are being stressed currently and am sure requests/requirements will only increase in a school environment especially since you say your Internet speed is scheduled to be increased.
I have overkilled my home, but things just work. Made up of Ubiquiti Unifi gateway Pro4 with UnfI AP-LR AP's. If you watch Ebay you might pick one up there, that is where I got my gateway.
UNDERSTAND this is a suggestion!
You could start with the Unifi security gateway pro4 and insert it into your existing network in place of the current router/dhcp server. Would give you much more control over dhcp as well as other things. You do have to install a controller application, but it will run on windows. The controller also gives lots of graphs of total bandwidth used, total by application and can drill down to an individual IP address and see what applications are taking how much bandwidth. Does take more effort and knowledge to setup that a consumer grade dumbed down router.
Link to how you would do the swap. https://help.ubnt.com/hc/en-us/articles/236281367-UniFi-USG-How-to-Adopt-a-USG-into-an-Existing-Network
It is certainly a better solution than a usual router, but the school has bought 8 Netgear R7800 to set up its wifi network, and I think the budget is empty now. Then, at first, I have to try to work with the NG routers. But I keep your solution as a possibility of "last chance".
Thaks a lot