Q:
My application uses CFNetServiceSetProtocolSpecificInformation or setProtocolSpecificInformation to advertise some meta-data corresponding to my Bonjour service, but sometimes I need to update this meta-data after the service is registered. Is that possible?
A: No. The only workaround is to completely unregister the service and then immediately re-register it with the new data. Unfortunately, this causes additional network traffic, so if you need to update this data often, then you should move completely to the low-level DNSServiceDiscovery API.
In Mac OS X 10.2.x, the function DNSServiceRegistrationUpdateRecord from the Mach-based DNSServiceDiscovery API will allow you to update the default TXT record for a service registration. If your application only requires Mac OS X 10.3 and later, you should use the socket-based DNSServiceDiscovery API instead of the Mach-based API. The function DNSServiceUpdateRecord will allow you to update the default TXT record for a service registration.
Both of these functions require that you specify the TTL (Time-to-Live) of the TXT record. The default TTL for TXT records in Mac OS X 10.2.x is 60 seconds, but the default TTL in Mac OS X 10.3.x is 240 seconds. It's recommended that you specify a value of 0 for the TTL, which will allow mDNSResponder to automatically choose the default value.
Document Revision History
| Date |
Notes |
| 2004-07-14 |
Simplified description of work around. |
| 2003-10-23 |
New document that explains how to update a Bonjour TXT record while running on either Jaguar or Panther. |
| 
