There is a domain, there is a DHCP server on win 2008 R2, there is a wifi AP on the D-link DWL-2100AP (DHCP is turned off on it). Some clients are connected to the network via wifi AP, these clients receive IP from the server, which are reserved for them by their MAC address.

Problem: if a client has not connected to the network for several days, then when trying to connect, he cannot get an IP address. If the wifi AP is restarted, then the address is received without problems. Logs on the server do not fix anything. Logs on the router write:

Association:11G STA (MAC) associated with WLAN1 SSID = (name)Received Disassoc: WLAN 1 11G STA (MAC)

Next in a circle.

  • DWL does not hang, clients work through it, which are included daily. I have two such APs, on both of which I tried to install d-link 615, the same. - hermit
  • The network is usually made (AD, DNS, DHCP), without segments, Internet access via TMG, DMZ is not, switches are used (with standard settings) HP ProCurve 1810G-24, HP ProCurve 1800-24G, HP ProCurve 1800-8G, HP ProCurve 2650. I did not try to sniff. - hermit
  • Yes, sniffers and will not help in this situation. These are different levels of the network. - sergarcada
  • Want to say the sniffer will not see requests? - e_klimin
  • It's one thing if requests do not come to the sideboard. Another, they come but there is no answer. Write comments addressed to me under my answer. - e_klimin

3 answers 3

There can be stupidly hanging DWL and the traffic does not pass. Check with static ip

  • one
    How is the network? What is online except for blood pressure? What comes to dhcp at the moment of not receiving ip (sniff)? - e_klimin
  • Using MS Network Monitor, I listened to the network in P-mode, as a result: it is clear that a broadcast request is coming from the client and the DHCP server responds to this request, but the answer does not reach the client and the request is repeated. Why he doesn’t receive it remains a mystery, obviously The answer is lost somewhere in the depths of the wifi AP. - hermit
  • firmware last? poppy of the sender in requests coincides with poppy of clients? There is a fitcha in some of the wifi modes, where the poppies are replaced, the toli wds, the toli client mode, although I'm not sure that this is on these points. wds enabled? - e_klimin
  • It is the penultimate, there is the last one, but it is beta and only problems with SSH are fixed there. Just as I already wrote, I tried another DIR-615 in AP mode, the same story. Perhaps this is only d-link devices such. - hermit
  • however, in my case, everything worked! yes by the way authentication is present? for the sake of a test, you can try without it, although it wakes up a reboot and everything will work well, this is on the sub-layers! - e_klimin 1:01 pm

This is how I present your situation. On your access point, DHCP is disabled and, accordingly, discards broadcast requests. That is, requests for DHCP on your AP do not go. On some routers there are so-called relay agents, in the settings this is indicated as DHCP Relay. Whether your AP has such a function - I can not say. Alternatively, create a separate pool for wi-fi clients and duplicate MAC binding on the access point. Of course, DHCP in this case will have to be enabled.

  • No, there is wifi with the eth bridge combined so it does not roll. DHCP Relay Those DHCP forward is not needed there. it is impossible to put another subnet on a Wi-Fi. - e_klimin
  • When a wireless client is connected, only the access point receives a broadcast request — and no one else. Logical network and do not need to break. You allocate a pool on your main DHCP server for wireless clients, say 10.0.1.16-10.0.1.24 - so that no one can take their addresses, we also do MAC binding. On the access point, we configure DHCP to issue addresses from 10.0.1.16-10.0.1.24 and also bind to the MAC. The bridge (network bridge, works at the network level) in this case does not affect anything, because it already works with a logical network, that is, ip-addresses that do not exist yet. - sergarcada
  • when the client connects, the request receives the entire network including those sitting on the wire. I had a similar scheme: the office had a server for 2003 visible with dhcp and 2 dwl 2100ap naturally dhcp, wifi was cut out for them ip clients from 2003 Windows. The problem with this model's dlink always arose with wpa2 authentication, but it was wep2, and here it is a little different. - e_klimin
  • Everything can be, with dwl-2100 I did not have anything and I will not argue. It can be when the DHCP relay agent is turned off and turns on automatically. But I also came across points that, for anything in the world, did not allow broadcast traffic through themselves, and those that required the manual activation of such a function. In principle, this functionality can be implemented programmatically. - sergarcada
  • yes there all is simple two interfaces are combined brctl and everything is stupid the bridge between interfaces. You can block traffic for example iptables. There is no firewall on DWL - e_klimin

If the M $ -mul is not used (or not critical) using MSDHCP-server to transfer client IP data to the MSDNS domain (used exclusively in MS servers), you can shift the duty of distributing the addresses from DLink to clients - it’s logical to assume that Such an implementation will improve the situation. Try it - an attempt is not torture.

  • Alas, we need exactly the described option. - hermit
  • then try what @sergarcada said I, in a timely manner, DFL-210 distributed IP, but allocated a pool for wifi clients. wifi handed out ZyXell P660EE. There were no jambs ... Authorization of DHCP in the domain passes normally? - Justicet
  • I made the AP itself distribute IP, but the story repeated. Yesterday I got IP on test devices and then turned them off, and clients worked until the end of the day. Today, customers continue to work without problems, but test devices cannot get IP. - hermit
  • Strange situation ... And what clients are on test devices? Terms of rent on the server? Stable clients received addresses from a separate pool? Stable customers also received IP from AR? Is IPv6 disabled on wifi clients? - Justicet