交换机NTP始终不优选服务器

1、交换机版本S12500G-AF-8055P03  R8055P03HS03；

2、按照官方文档配置ntp后，发现始终无法优选ntp服务器，ntp服务器是可达的，其他地市的相同配置均正常。

 clock protocol ntp

 ntp-service enable

 ntp-service refclock-master 3

 ntp-service unicast-server 120.52.51.149

 ntp-service unicast-server 120.52.51.148 priority

3、dis ntp sessions显示如下；

       source          reference       stra reach poll  now offset  delay disper

********************************************************************************

   [25]120.52.51.148   TFT                1   255   64   35 589.78 24.841 4.3335

   [25]120.52.51.149   TFT                1   255   64    9 591.83 23.391 1.9073

[12345]LOCAL(0)        127.127.1.0        2   255   64   45 0.0000 0.0000 0.9155

Notes: 1 source(master), 2 source(peer), 3 selected, 4 candidate, 5 configured.

 Total sessions: 3

4、尝试debugging ntp-service all，截取相关内容如下；

*Jul 18 11:23:51:812 2024 csw_hostname NTP/7/ACL: Access restrict: 0x00000004.

*Jul 18 11:23:51:812 2024 csw_hostname NTP/7/AUTH: Received a packet at 69521, from 120.52.51.149, mode 4, key ID 00000000, length 48, authentication result 0

*Jul 18 11:23:51:812 2024 csw_hostname NTP/7/PARAM: Clock filter param: number 8, offset 0.198977, delay 0.023160, dispersion 0.003072, jitter 0.001260, burst 0

*Jul 18 11:23:51:813 2024 csw_hostname NTP/7/SELECT: peer 120.52.51.148, flash 0x00001000, flags 0x00000621, reach 255, root distance 0.029300

*Jul 18 11:23:51:813 2024 csw_hostname NTP/7/SELECT: peer 120.52.51.149, flash 0x00001000, flags 0x00000601, reach 255, root distance 0.026166

*Jul 18 11:23:51:813 2024 csw_hostname NTP/7/SELECT: Survivor 127.127.1.0, distance 0.000000

*Jul 18 11:23:51:813 2024 csw_hostname NTP/7/SELECT: Combine offset 0.000000000, jitter 0.000000119

*Jul 18 11:23:51:813 2024 csw_hostname NTP/7/SYNCH: Synchronized to peer 127.127.1.0

*Jul 18 11:23:51:813 2024 csw_hostname NTP/7/SELECT: Clock update at 69521, sample 69505, session ID 54648, offset 0.000000

*Jul 18 11:23:52:855 2024 csw_hostname NTP/7/PACKET_RECV: 

 packet from 10.0.0.6 to 10.0.0.1 on Vlan-interface101 

 leap: 0, version: 4, mode: 3, vrfindex: 1 

 stratum:  4, poll: 6, precision: 2^-22 

 rdel: 1.541, rdsp: 19.547, refid: 10.14.171.1 

 reftime: ea430907.db4e55f1  Thu, Jul 18 2024 11:22:47.856 

 orgtime: ea430907.db035755  Thu, Jul 18 2024 11:22:47.855 

 rectime: ea430907.db4e55f1  Thu, Jul 18 2024 11:22:47.856 

 xmttime: ea430948.dad22c5f  Thu, Jul 18 2024 11:23:52.854 

 inptime: ea430948.dafd97d5  Thu, Jul 18 2024 11:23:52.855 

5、求解，谢谢！