I sniffed with TCPDUMP in my FreeBSD netbook what's going on on first requesting with firefox some web page: FF starts and asks the (local) DNS at IP port 53 for the IP addr of A? detectportal.firefox.com DNS answer: CNAME detectportal.firefox.com.edgesuite.net., CNAME a1089.d.akamai.net., A FF makes HTTP request to and sends HTTP: GET /success.txt (and this is perhaps not the answer of, but sent by the local AP): HTTP/1.0 302 Moved Temporarily Location: which FF now let bring up the landing/login page of the AP But, this (HTTP redirect) is only one of more arts to direct a browser to a login page; see also: https://en.wikipedia.org/wiki/Captive_portal I also would suggest a good organized description in the Wiki about some common methods to try in UT/UB to get to the login page of the local Wifi AP. matthias