NSNetServiceBrowser did not search with error -72008 on iOS 14

Question

The same error is also triggered setting up Multipeer Connectivity (which uses Bonjour). The code I was using for initiating Bonjour browsing and Multipeer Connectivity was modified from the Apple sample code and worked fine under iOS 13.

Answer 1

You need to add the following keys to the Info.plist: NSLocalNetworkUsageDescription and NSBonjourServices. E.g.

<key>NSLocalNetworkUsageDescription</key>
<string>Reason for using Bonjour that the user can understand</string>
<key>NSBonjourServices</key>
<array>
    <string>_my-service._tcp</string>
    <string>_my-service._udp</string>
</array>

Ensure that my-service is correctly named for your service name. E.g. if your are setting up MPC for a "foobar" service, you might have

mpcAdvertiserAssistant = MCAdvertiserAssistant(serviceType: "foobar", discoveryInfo: discoveryInfoDict, session: mpcSession)

and so you would use

<string>_foobar._tcp</string>
<string>_foobar._udp</string>

(You might not require both TCP and UDP in your implementation.)

See https://developer.apple.com/videos/play/wwdc2020/10110/

and https://developer.apple.com/forums/thread/653316