I have a central router that synchronizes with a public NTP server. This router acts as a master for the routers at our branch offices over an MPLS connection. Four out of the five branch office routers have synchronized with our main router, but one is stuck in stratum 16. I have the NTP configurations on all of the branch office routers the same except for different MD5 authentication keys. One strange thing to note is that a debug authentication on the trouble router shows Authentication key 0 instead of 1. I have completely removed the NTP commands on the trouble router and entered them back in with no luck. I also tried manually setting the clock hoping it would update. Below are the configs of our main router, a successful branch router, and the trouble router. Any advice pointing in the right direction is always appreciated!
GoodRouter#show ip int brief | i Loopback
Loopback0 10.0.255.6 YES NVRAM up up
GoodRouter#show run | s ntp
ntp authentication-key 1 md5 032F4E520318347B1D 7
ntp authenticate
ntp trusted-key 1
ntp clock-period 17180202
ntp source Loopback0
ntp master 3
ntp update-calendar
ntp server x.x.x.x
ntp server y.y.y.y
ntp server z.z.z.z
GoodBranch#show run | s ntp
ntp authentication-key 1 md5 132E024B0E1B111D78 7
ntp authenticate
ntp trusted-key 1
ntp source Loopback0
ntp server 10.0.255.6 key 1
BadBranch#show run | s ntp
ntp authentication-key 1 md5 774BE5A9F0FD806086 7
ntp authenticate
ntp trusted-key 1
ntp source Loopback0
ntp server 10.0.255.6 key 1
