I'm a Network Administrator, but I'm not sure how to proceed. I have a Technicolor TC8305C DOCSIS gateway, the Comcast brand. Every few months, I find some Apple devices will not properly negotiate DHCP leases via WLAN. I am at my wits end with this problem and nothing I do seems to resolve it. Two examples of such devices are an Apple iPhone 5, and an Apple iPad Air. The router's WLAN is set to 802.11 g/n, with WPA/WPA2-PSK (TKIP/AES) encryption.
Upon connecting to the wireless router, and typing in the correct password, something goes wrong with DHCP. The device defaults to the 169.254.0.0/16 autoconfiguration address. Checking the router's web GUI, I can see that it has assigned the device a class A IP address, and can see its MAC address and hostname. On the Apple device the Wi-Fi symbol is not displayed in the upper icon bar. Obviously, there has been a breakdown in the DHCP lease negotiation process, and/or there is a different sort of issue on one of the devices. I do not know how to rule out either device as being the cause of the problem.
When I set a static IP address on the Apple device, I still do not have connectivity, though the Wi-Fi symbol is displayed in the upper icon bar. I have verified the manually entered information is 100% correct. Setting a static (reserved) IP address in the router's web GUI, assigning it to the Apple device's MAC address, also has no effect.
I have tested the connection with the following methods, all of which result in a "host unreachable" result:
- Ping from a known connected host on the network (from a PC).
- Ping from the router's web GUI.
- Ping from the Apple device to a known connected host on the network (to a PC).
I have tried resetting the router, the Apple devices, turning off AirDrop on the Apple devices, and doing a factory reset on the router. None of these are a solution, however doing a factory reset on the router seems to temporarily alleviate the problem about 20% of the time (it is mostly ineffectual). The only other thing I can think to do is a packet capture from my IDS/Wireshark, in an attempt to narrow down the problem.