On some distribution points in ConfigMgr, the WDS service may not start on Windows Server 2012 R2, which would prevent PXE boot. Trying to start the service produce error 0x2 in the event logs. This problem is likely being caused by the multicast option for the DP.
The fix is simple:
1. Remove the multicast option on the ConfigMgr DP role for that server. The logs can be monitored for removal completion in \\servername\drive$\sms\logs\
2. Start the WDS service. If there is still an error, a reinstall of WDS may be necessary prior to continuing.
3. Re-add the multicast option and monitor the logs for completion
4. Restart the WDS service to verify it can still start
It also does not appear that Update 1 (KB2883200) for WinSvr 2012 R2 has a positive impact to prevent this, but it may. So I recommend setting up your monitoring tools to watch the state of this service.