A Look at Wifi in McDonalds

2018-04-30

Sometimes I like using my computer not at home. Working on personal projects or just casually web-surfing, I end up using public wifi a lot. One such time I was in the local McDonalds using the free wifi and after noticing a very prominent router above my head, became curious on what kind of wifi service was being provided. So I’ve ended up writing this tiny informal review of the public wifi experience here in the McDonalds, Harvey Center, Harlow.

The Wifi

As clear from both the in store logos and the branding on the captive portal when logging in, the ISP of the wifi service is O2, a UK only telecommunications provider. It’s not clear if being an O2 customer yields any additional benefit when using the wifi here (as I am not one), but the captive portal does provide an option to login with an O2 customer account.

There are two available SSIDs for the service; McDonald's Free Wifi and O2 Wifi. Presumably the O2 SSID is for the benefit of O2 customers in which they provide wifi access points for them with a shared SSID. As with most public wifi, the access point for these SSIDs was unsecured, with no form of encrypted access between device and access point offered. The wifi access points themselves were Cisco branded.

Connecting to access point and trying to access the internet will trigger the captive portal, which gates internet connectivity by a mandatory login. You can login either by using a McDonalds wifi account or using an O2 customer account, as mentioned above. The captive portal also allows you to register a McDonalds wifi account if you don’t have one. From a small sample size of visiting 7 McDonalds locations across England and Wales, this account seemed to allow access to all these locations.

Any unencrypted HTTP traffic will be automatically redirected to the captive portal upon connection. However, encrypted traffic will bypass the captive portal entirely and allow you to access the internet as normal. SSH connections will also bypass the captive portal login requirement.

Internet connection quality was quite good, with no problems encountered in regular usage after correctly authorising via the captive portal login. However there was some misconfiguration of IP addresses within the access points. Attempting to access the IPv4 address 1.1.1.1 will redirect to a Cisco wireless admin login page. As a result, Cloudflare DNS will not work here. Attempting to access the IPv4 addresses 8.8.8.8/8.8.4.4 will result in the connection immediately timing out. As a result, Google DNS will not work here.

A small speed test was conducted at 17:06 using speedtest.net:

Attempt Ping (ms) DL (Mbps) UP (Mbps)
0 28 23.67 7.65
1 27 31.64 8.27
2 23 25.19 8.43