US 12,192,316 B2
Method to eliminate clock synchronization from undesired clock sources
Sreejith Avikkal, Ottawa (CA); Nancy Patricia Cam-Winget, Mountain View, CA (US); Lizbeth Berenice Guerra Martinez, Mexico City (MX); Natasha Wong, Torrance, CA (US); and Jessica Lynne Poole, Oakland, CA (US)
Assigned to Cisco Technology, Inc., San Jose, CA (US)
Filed by Cisco Technology, Inc., San Jose, CA (US)
Filed on Dec. 21, 2021, as Appl. No. 17/558,313.
Prior Publication US 2023/0198738 A1, Jun. 22, 2023
Int. Cl. H04L 9/40 (2022.01); H04L 7/10 (2006.01); H04L 9/32 (2006.01)
CPC H04L 7/10 (2013.01) [H04L 9/3247 (2013.01); H04L 9/3297 (2013.01); H04L 63/0876 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method performed at least partly by a controller that monitors devices within a network, the method comprising:
receiving a first request from a first device to authenticate a role of the first device as a grandmaster in a precision time protocol (PTP);
granting the first request designating the role of the first device as the grandmaster;
receiving a second request from a second device to authenticate that a clock announce message from the first device is from an authorized grandmaster;
determining whether the first device is authorized to send the clock announce message to the second device; and
in response to determining the first device is authorized to send the clock announce message, sending to the second device a message indicating that the first device is authorized as the grandmaster and granting permission for the second device to sync with the first device; or
in response to determining that the first device is not authorized to perform the clock announce message, sending to the second device, a message indicating that the first device is not authorized as the grandmaster and denying permission for the second device to sync with the first device.