Strange IPs for wireless clients

[knut]

I noticed after upgrading mye fortigate 200b to 4.0 mr3 patch 2 (previously I ran the latest mr2 specific fortiap build). I also got the latest 219 build on the access points. Here is one of the clients (probably an samsung galaxy s that we got quite a few of, but most of the mac addresses with this problem appears to be from Apple): 66 2011-10-06 17:16:16 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 67 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 68 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 69 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 70 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 71 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 72 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 73 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 74 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 75 2011-10-06 17:16:15 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. 76 2011-10-06 17:16:14 notice client-ip-detected Client 78:d6:f0:9d:0e:c0 assigned an IP address. First the client ip is: 192.168.12.137 (that is a correct address in that wireless network), then it changes to 46.67.129.69 and back and forth. Every single one of those events was from the same access point. One of the other clients alternates 6 times between 192.168.122.110 and 10.0.1.9 within one second. The 192.168.122.110 is the correct address for that ssid. The mac address for this client starts with 24:ab:81, and belongs to Apple. This particular SSID have regular 6 changes back and forth with those two IP-s, up to 6 times a minute. There is also a client that alternates between three different ips: 192.168.122.103, 192.168.1.113, 192.168.2.4. The networks I got in the firewall is 192.166.122.0/24 (one of the two wireless networks), 192.168.12.0/24 (the second of the two wireless networks), two routed interfaces with public ip-adresses, and the last one that got 192.168.18.0/24. So I have no idea where the other ip-adresses come from. The wireless network is quite unstable. I use one guest-network (192.168.122.0/24) with some firewall rules that allows some internet-access, and restricted speed. This is only available at the 2.4 GHz band, and is currently without encryption or a captive portal. The other network got access to the local networks, as well as Internet without speed restrictions. This is available for both 2.4 and 5 GHz and is protected with WPA2-AES.

[yzhang_FTNT]

What' s the meaning of " The wireless network is quite unstable" ? The controller detects the client' s IP address through the IP packet send from the client. If the client is a multi-homed host, sometimes it can send IP packet through the wireless interface using other interface' s IP. That' s should be the reason that you saw some clients' IP back and forth changing.

[knut]

The wireless network gets extremely slow and halts to a stop for , even though there are not much traffic going thrugh it (it averages around 300 Kbps during work hours). I got 3 FortiAP and usually around 30-40 clients in total and they are distributed quite even. I don' t think that it is usual to go back and forth with the IP 6 times within a second, not even 6 times within a second 6 times a minute.