See comment in accepted answer for the likely problem source.
I'm using my laptop (an early 2013 Retina MacBook Pro running OS 10.9.1) on a campus network. I have had random disconnection issues on this (and only this) network. The problem occurs as follows. After some time of working fine (usually an hour or two), I begin being disconnected from the network consistently. I can stay connected for maybe 10 or 20 seconds before being disconnected again. When I am disconnected, the computer gives itself a self-assigned IP address, and maybe a minute later is (sometimes) able to get a new address from the DHCP server. If I manually renew the DHCP lease (sometimes) or if I turn Wi-Fi off and on (almost all the time), it connects again, but only for another 20 seconds. A reboot does not help; it begins the disconnect cycles immediately on boot.
I've contacted the network support team several times and talked to them in person several more times, but they've been unable (or maybe unwilling) to track down the problem. I want to make sure that there's no problem with my system. I'm suspicious since my iPhone and iPad both have no problems. The laptop, however, has no problems on other networks (ever) so I'm just not sure. The fact that only the laptop is doing it suggests it may be having trouble, but all other networks are fine, which suggests the network is at fault.
I'm mainly looking for suggestions of what problems could cause this behavior, and where appropriate, solutions (either complete or partial) that might fix them. What techniques can I use to track down the real source of this problem?
Best Answer
For starters you could try a simple ping to a popular outside URL, like yahoo.com or google.com, let it run like 10-15 times, maybe more, and see if the connection gets no response in any of the pings. That will show you your connection on that network isn't consistent.
There are also various Wi-Fi network optimization settings, so something that benefits them the most in crowded areas may not be working for your machine. If they are testing newer Wi-Fi frequencies, like AC or even some variant of N, you may not be the only person affected with a new MacBook on campus.