ntpd ignoring resolv.conf
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Date: Tue, 24 Sep 2024 06:16:16 UTC
Hi there, I'm on FreeBSD 14.1-RELEASE-p5. I noticed that on my computer ntpd does not synchronize the time correctly. In /var/log/messages I get the following errors: Sep 24 07:38:38 ufr-t14 ntpd[33259]: error resolving pool 0.de.pool.ntp.org: Name does not resolve (8) Sep 24 07:38:39 ufr-t14 ntpd[33259]: error resolving pool 1.de.pool.ntp.org: Name does not resolve (8) Sep 24 07:38:40 ufr-t14 ntpd[33259]: error resolving pool 0.freebsd.pool.ntp.org: Name does not resolve (8) Sep 24 07:38:41 ufr-t14 ntpd[33259]: error resolving pool 2.freebsd.pool.ntp.org: Name does not resolve (8) With the help of people from the FreeBSD forum (https://forums.freebsd.org/threads/no-name-resolution-within-ntpd.95065/) I found out that ntpd tries to connect to a DNS server on the loopback interface and not the one configured in resolv.conf. When I restart ntpd, tcpdump shows the following: # tcpdump -i lo0 -nl -vvv port 53 tcpdump: listening on lo0, link-type NULL (BSD loopback), snapshot length 262144 bytes 07:40:45.091595 IP (tos 0x0, ttl 64, id 62263, offset 0, flags [none], proto UDP (17), length 63, bad cksum 0 (->8974)!) 127.0.0.1.53752 > 127.0.0.1.53: [bad udp cksum 0xfe3e -> 0xfed9!] 63331+ A? 0.de.pool.ntp.org. (35) 07:40:45.091627 IP6 (flowlabel 0xe3ce5, hlim 64, next-header UDP (17) payload length: 43) ::1.62965 > ::1.53: [bad udp cksum 0x003e -> 0xd8dd!] 63331+ A? 0.de.pool.ntp.org. (35) 07:40:45.091645 IP (tos 0x0, ttl 64, id 62264, offset 0, flags [none], proto UDP (17), length 63, bad cksum 0 (->8973)!) 127.0.0.1.65074 > 127.0.0.1.53: [bad udp cksum 0xfe3e -> 0xd29f!] 63331+ A? 0.de.pool.ntp.org. (35) 07:40:45.091662 IP6 (flowlabel 0x8f26d, hlim 64, next-header UDP (17) payload length: 43) ::1.61503 > ::1.53: [bad udp cksum 0x003e -> 0xde93!] 63331+ A? 0.de.pool.ntp.org. (35) 07:40:46.092343 IP (tos 0x0, ttl 64, id 62265, offset 0, flags [none], proto UDP (17), length 63, bad cksum 0 (->8972)!) There is no nameserver entry for 127.0.0.1 in my res resolv.conf: # cat /etc/resolv.conf # Generated by resolvconf search rz.privat nameserver 192.168.88.1 nameserver 132.230.200.200 nameserver 132.230.201.111 For some strange reason ntpd ignores resolv.conf and expects a DNS server on the loopback interface. As a workaround I configured local_unbound in rc.conf. Now, with a DNS server running on the loopback interface and without configuring it in resolv.conf, ntpd is working correctly. Is there a way to configure ntpd in a way that it uses the DNS servers configured in resolv.conf? Thanks in advance. Markus