nslookup is fast (including for addresses I’ve not looked up before) and ping is fast (~10ms) to a range of addresses. curl google.com can take two minutes to return anything, but once established connections seem to give fast download speeds.
This is on a home Wi-Fi network (Compal CH7485E model router, 2.4 and 5 GHz, 802.11b/g/n), affects some devices (Mac OS X, Android phone) but not others (Windows, Linux laptops), and seems not to be affected by a choice of Wi-Fi channel or frequency. Changing DNS servers, e.g. to Google DNS, doesn’t help. Wired connections seem to be fine.
What could cause such behaviour?
