Firewall Blocking an NTP Server from pool.ntp.org - Rogue NTP Server?

As @grifferz indicated, the fact that it’s included in queries under pool.ntp.org means it is serving NTP and the time being served is in the ballpark (I think within 15ms, but it might be 75ms, certainly within 0.1s).

You can see this yourself with a query using ntpdate with -q or -d to query without setting the clock:

C:\Users\daveh\OneDrive\Documents>ntpdate -d -p 3 ntp.md
24 Jun 18:25:03 ntpdate[41164]: ntpdate 4.2.8p18@1.4062-o Jun 11 5:31:11.85 (UTC-00:00) 2025  (2)
host found : ntp.md
24 Jun 18:25:03 ntpdate[41164]: Raised to high priority class, realtime requires Increase Scheduling Priority privilege (enabled with secpol.msc).
Looking for host ntp.md and service ntp
2001:470:e114::123 reversed to ntp.md
transmit(2001:470:e114::123)
receive(2001:470:e114::123)
transmit(38.81.211.177)
receive(38.81.211.177)
transmit(2001:470:e114::123)
receive(2001:470:e114::123)
transmit(38.81.211.177)
receive(38.81.211.177)
transmit(2001:470:e114::123)
receive(2001:470:e114::123)
transmit(38.81.211.177)
receive(38.81.211.177)

server 2001:470:e114::123, port 123
stratum 1, precision -22, leap 00, trust 000
refid [GPPS], root delay 0.000000, root dispersion 0.001373
reference time:      ec056bea.f8da5eda  Tue, Jun 24 2025 18:24:42.972
originate timestamp: ec056c04.25ec475a  Tue, Jun 24 2025 18:25:08.148
transmit timestamp:  ec056c04.250fadf3  Tue, Jun 24 2025 18:25:08.144
filter delay:  0.03152    0.03130    0.03003    ----
               ----       ----       ----       ----
filter offset: +0.000928  +0.000742  +0.001086  ----
               ----       ----       ----       ----
delay 0.03003, dispersion 0.00020, offset +0.001086

server 38.81.211.177, port 123
stratum 1, precision -22, leap 00, trust 000
refid [GPPS], root delay 0.000000, root dispersion 0.001373
reference time:      ec056bea.f8da5eda  Tue, Jun 24 2025 18:24:42.972
originate timestamp: ec056c04.5aa43722  Tue, Jun 24 2025 18:25:08.354
transmit timestamp:  ec056c04.59bf26f2  Tue, Jun 24 2025 18:25:08.350
filter delay:  0.03394    0.03630    0.03177    ----
               ----       ----       ----       ----
filter offset: +0.002609  +0.002921  +0.000382  ----
               ----       ----       ----       ----
delay 0.03177, dispersion 0.00172, offset +0.000382

24 Jun 18:25:08 ntpdate[41164]: adjust time server 2001:470:e114::123 offset +0.001086 sec

C:\Users\daveh\OneDrive\Documents>