@Roro747 ,

The range is 10.10 to 11.254... In other words, 10.10 to 10.254 and 11.1 to 11.254. That's nearly 500.

  @Roro747 ,

BTW, you might want to upgrade that router. The current firmware version is 2.2.6...

From 10.10 to 11.254 are 499 ip. You have set the starting ip to 10.9

  @EricPerl 

ha just make the update for 2.2.5 and now 2.2.6

the question is that I have almost 300 devices and I am blocked at 244 and the router no longer assigns me an IP on the network. i dont uderstand why im stuck with this settings 

  @Roro747 ,

Hmm, all your clients ended up in the 10.xxx range?

None of them got 11.xxx addresses?

And new ones now get 169.254.xxx addresses?

Did you make any reservations that could get in the way?

Anything special about the clients being added?

  @Roro747 

I have a lot of IPs in 192.168.10.XX and a few in 192.168.11.XX.

The new ones do not receive an IP and cannot connect to the network because no IP is available.

Yes I made all the IP reservations so that the IPs don't change. Could this interfere with the assignment of IPs with dhcp?

a friend told me the ER 605 is not designed to manage that much equipment, physically: The ER7206 can manage up to 500 ip Against 100 max recommended for the ER605. thx for your help. must change my equipment :/

  @Roro747 ,

I actually had checked that aspect already.

TL-R605, max DHCP reservations? - Business Community (tp-link.com)

That's a reply from staff... the limit was 1024 on the v1. I'd be surprised it was brought down on v2 (which is more capable in many ways).

I realize it's about reservations but I'm not entirely sure how it would make sense if the server could not handle as many leases.

And then there's this:

Model: ER605 (TL-R605) Maximum DHCP Scope? 6,000 leases required - Business Community (tp-link.com)

It's less authoritative though... but it's the same number.

It's the same limit on the 7206 BTW (per another reply from staff).

DHCP is unlikely the thing that's going to push the limit on the router.

Number of concurrent sessions and throughput are more concerning. You can look up the specs of each device for that.

I was asking about 11.xx to make sure the DHCP server handled the /23 properly.

The fact that some exist (auto-assigned) is a good sign.

Reservations can get in the way. Let's say you made 250 in range reservations for clients not yet on the network, add 250 clients that get aren't reserved, you're stuck.

Up to some point, not yet expired leases can get in the way as well. You add 250 clients quickly, power them off. For couple hours (with your by default setting), these 250 addresses can't be assigned to new clients...

Anyway, enjoy the new hardware. 

  @Clive_A ,

By the way, I suspect none of these limits are documented (designed for 60-80, hard fail at ~250).

I also suspect the failure didn't generate any logs. Wouldn't it be nice if end customers could diagnose some of these failures?