driftfile /var/lib/ntp/ntp.drift
leapfile /usr/share/zoneinfo/leap-seconds.list

# Redundant upstream time sources: pfv-netinfra-01/02 (Technitium/Pi-hole hosts
# also serving NTP). IPs are used (not hostnames) because the knel.net name for
# these hosts resolves to a Tailscale CGNAT address, not the LAN address, and
# because NTP must come up before DNS is available. iburst speeds initial sync.
server 192.168.3.252 iburst
server 192.168.3.253 iburst

# Hardened client: sync from the configured servers but never serve time to
# anyone else. Note: `interface listen 127.0.0.1` must NOT be used here — it
# binds ntpd to loopback, making outbound queries carry a 127.0.0.1 source
# address that upstream servers cannot reply to (symptoms: peers stuck in
# .INIT. with reach 0). Use restrict rules to control access instead.
restrict default ignore
restrict 127.0.0.1
restrict ::1
restrict 192.168.3.252 nomodify notrap nopeer
restrict 192.168.3.253 nomodify notrap nopeer