0

Issue

Hello, I got an ntp problem. It is always occurred with ntpd version 4.2.2, rhel6. rhel7 now uses ntpd-4.2.6, but some system also use ntpd-4.2.2. I have hundreds of machines running ntpd-4.2.2 but half of them sync failed and select itself intermittently. I don't know why this phenomenon occurred? Is this ntpd's bug?

client: dmsag(10.13.1.41)
SERVER: 10.13.2.1, 10.13.2.2

Client NTP version:

[root@r7f560156.cloud.am65:/root]
#ntpd --version
ntpd: ntpd 4.2.2p1@1.1570-o Mon Dec 29 09:33:00 UTC 2014 (1)

client NTP configuration:

[root@dmsag /root]
#cat /etc/ntp.conf

driftfile /var/lib/ntp/drift
pidfile /var/run/ntpd.pid
#logfile /var/log/ntp.log

# Access Control Support
restrict    default ignore
restrict -6 default ignore
restrict    127.0.0.1

restrict    10.13.2.1
restrict    10.13.2.2
# local clock
server 127.127.1.0
fudge 127.127.1.2 stratum 10


server 10.13.2.1 iburst minpoll 4 maxpoll 6 prefer
server 10.13.2.2 iburst minpoll 4 maxpoll 6

server NTP version:

[root@r7f4a4100 ~]# ntpd --version
ntpd 4.2.6p5
ntpd 4.2.6p5@1.2349-o Sat Dec 20 11:11:28 UTC 2014 (1)

There are package exchanges between client with server

[root@dmsag /root]
#tcpdump -i any host 10.13.2.2 and port 123 -nn
tcpdump: WARNING: Promiscuous mode not supported on the "any" device
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on any, link-type LINUX_SLL (Linux cooked), capture size 96 bytes

13:05:44.366753 IP 10.13.1.41.123 > 10.13.2.2.123: NTPv4, Client, length 48
13:05:44.372187 IP 10.13.1.41.123 > 10.13.2.2.123: NTPv4, Client, length 48
13:05:44.366923 IP 10.13.2.2.123 > 10.13.1.41.123: NTPv4, Server, length 48
13:06:48.366735 IP 10.13.1.41.123 > 10.13.2.2.123: NTPv4, Client, length 48
13:06:48.366739 IP 10.13.1.41.123 > 10.13.2.2.123: NTPv4, Client, length 48
13:06:48.366896 IP 10.13.2.2.123 > 10.13.1.41.123: NTPv4, Server, length 48
^C
6 packets captured
6 packets received by filter
0 packets dropped by kernel

client always select itself

[root@dmsag /root]
#ntpq -np
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*127.127.1.0     .LOCL.           5 l   63   64  377    0.000    0.000   0.001
 10.13.2.1       10.98.94.5       4 u   26   64  377    0.108   -9.741   4.278
 10.13.2.2       10.98.94.5       4 u   23   64  377    0.118  -12.981   5.226

ntp server

[root@dmsag /root]
#ssh 10.13.2.1
Last login: Thu Feb  9 13:02:29 2017 from testx.tbsite.net
[root@r7f4a4100 ~]# ntpq -np
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 127.127.1.0     .LOCL.           5 l  88m   64    0    0.000    0.000   0.000
*10.98.94.5      40.118.106.130   3 u   17   64  377    0.378   23.436  11.696
 10.13.2.1       .INIT.          16 u    -   16    0    0.000    0.000   0.000
+10.13.2.2       10.98.94.5       4 u   11   16  376    0.389    5.377   1.966

DEBUG

strace

[root@dmsag /root]
#strace -p 32121
Process 32121 attached - interrupt to quit
select(19, [16 17 18], NULL, NULL, NULL) = ? ERESTARTNOHAND (To be restarted)
--- SIGALRM (Alarm clock) @ 0 (0) ---
rt_sigreturn(0xe)                       = -1 EINTR (Interrupted system call)
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\1\0\1\0\0\0\0\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef4704, 1092, 0, 0x7fdf33ef45e0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\201\0\1\300\21\0\0\0\0\0\fqb\220\24qc\220\24qd\220\24", 24, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, 16) = 24
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\2\0\0qb\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef51f4, 1092, 0, 0x7fdf33ef50d0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\2\220\24qb\0\0\1\324srcadr=127.127.1.0, "..., 480, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\2\220\24qb\1\324\0\201offset= 0.00 0.00 0."..., 144, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, 16) = 144
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\3\0\0qc\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef5ce4, 1092, 0, 0x7fdf33ef5bc0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\3\220\24qc\0\0\1\322srcadr=10.13.2.1, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\3\220\24qc\1\322\0qfiltoffset= -8.65 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\4\0\0qd\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef67d4, 1092, 0, 0x7fdf33ef66b0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\4\220\24qd\0\0\1\322srcadr=10.13.2.2, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\4\220\24qd\1\322\0qfiltoffset= -9.52 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(55549), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = ? ERESTARTNOHAND (To be restarted)
--- SIGALRM (Alarm clock) @ 0 (0) ---
rt_sigreturn(0xe)                       = -1 EINTR (Interrupted system call)
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\1\0\1\0\0\0\0\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef72c4, 1092, 0, 0x7fdf33ef71a0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\201\0\1\300\21\0\0\0\0\0\fqb\220\24qc\220\24qd\220\24", 24, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, 16) = 24
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\2\0\0qb\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef6d4c, 1092, 0, 0x7fdf33ef6c28, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\2\220\24qb\0\0\1\324srcadr=127.127.1.0, "..., 480, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\2\220\24qb\1\324\0\201offset= 0.00 0.00 0."..., 144, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, 16) = 144
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\3\0\0qc\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef4c7c, 1092, 0, 0x7fdf33ef4b58, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\3\220\24qc\0\0\1\322srcadr=10.13.2.1, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\3\220\24qc\1\322\0qfiltoffset= -8.65 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\4\0\0qd\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef576c, 1092, 0, 0x7fdf33ef5648, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\4\220\24qd\0\0\1\322srcadr=10.13.2.2, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\4\220\24qd\1\322\0qfiltoffset= -9.52 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(45660), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = ? ERESTARTNOHAND (To be restarted)
--- SIGALRM (Alarm clock) @ 0 (0) ---
rt_sigreturn(0xe)                       = -1 EINTR (Interrupted system call)
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\1\0\1\0\0\0\0\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef625c, 1092, 0, 0x7fdf33ef6138, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\201\0\1\300\21\0\0\0\0\0\fqb\220\24qc\220\24qd\220\24", 24, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, 16) = 24
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\2\0\0qb\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef783c, 1092, 0, 0x7fdf33ef7718, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\2\220\24qb\0\0\1\324srcadr=127.127.1.0, "..., 480, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\2\220\24qb\1\324\0\201offset= 0.00 0.00 0."..., 144, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, 16) = 144
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\3\0\0qc\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef4704, 1092, 0, 0x7fdf33ef45e0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\3\220\24qc\0\0\1\322srcadr=10.13.2.1, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\3\220\24qc\1\322\0qfiltoffset= -8.65 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\4\0\0qd\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef51f4, 1092, 0, 0x7fdf33ef50d0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\4\220\24qd\0\0\1\322srcadr=10.13.2.2, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\4\220\24qd\1\322\0qfiltoffset= -9.52 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(37351), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\1\0\1\0\0\0\0\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef5ce4, 1092, 0, 0x7fdf33ef5bc0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\201\0\1\300\21\0\0\0\0\0\fqb\220\24qc\220\24qd\220\24", 24, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, 16) = 24
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\2\0\0qb\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef67d4, 1092, 0, 0x7fdf33ef66b0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\2\220\24qb\0\0\1\324srcadr=127.127.1.0, "..., 480, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\2\220\24qb\1\324\0\201offset= 0.00 0.00 0."..., 144, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, 16) = 144
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\3\0\0qc\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef72c4, 1092, 0, 0x7fdf33ef71a0, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\3\220\24qc\0\0\1\322srcadr=10.13.2.1, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\3\220\24qc\1\322\0qfiltoffset= -8.65 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = 1 (in [17])
select(19, [16 17 18], NULL, NULL, {0, 0}) = 1 (in [17], left {0, 0})
recvfrom(17, "\26\2\0\4\0\0qd\0\0\0\0", 1092, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, [16]) = 12
recvfrom(17, 0x7fdf33ef6d4c, 1092, 0, 0x7fdf33ef6c28, 0x7fffe66de59c) = -1 EAGAIN (Resource temporarily unavailable)
sendto(17, "\326\242\0\4\220\24qd\0\0\1\322srcadr=10.13.2.2, sr"..., 480, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, 16) = 480
sendto(17, "\326\202\0\4\220\24qd\1\322\0qfiltoffset= -9.52 -9"..., 128, 0, {sa_family=AF_INET, sin_port=htons(52421), sin_addr=inet_addr("127.0.0.1")}, 16) = 128
select(19, [16 17 18], NULL, NULL, NULL) = ? ERESTARTNOHAND (To be restarted)

ntpd debug infomation

[root@dmsag /root]
#ntpd -d
ntpd 4.2.2p1@1.1570-o Mon Dec 29 09:33:00 UTC 2014 (1)
addto_syslog: precision = 1.000 usec
create_sockets(123)
addto_syslog: no IPv6 interfaces found
addto_syslog: ntp_io: estimated max descriptors: 655360, initial socket boundary: 16
bind() fd 16, family 2, port 123, addr 0.0.0.0, flags=9
Added addr 0.0.0.0 to list of addresses
addto_syslog: Listening on interface wildcard, 0.0.0.0#123 Disabled
bind() fd 17, family 2, port 123, addr 127.0.0.1, flags=5
Added addr 127.0.0.1 to list of addresses
addto_syslog: Listening on interface lo, 127.0.0.1#123 Enabled
bind() fd 18, family 2, port 123, addr 10.13.1.41, flags=25
Added addr 10.13.1.41 to list of addresses
addto_syslog: Listening on interface bond0, 10.13.1.41#123 Enabled
init_io: maxactivefd 18
local_clock: time 0 base 0.000000 offset 0.000000 freq 0.000 state 0
addto_syslog: frequency initialized 51.952 PPM from /var/lib/ntp/drift
key_expire: at 0
peer_clear: at 0 next 1 assoc ID 57098 refid INIT
newpeer: 127.0.0.1->127.127.1.0 mode 3 vers 4 poll 6 10 flags 0x1021 0x1 ttl 0 key 00000000
key_expire: at 0
peer_clear: at 0 next 2 assoc ID 57099 refid INIT
newpeer: 10.13.1.41->10.13.2.1 mode 3 vers 4 poll 4 6 flags 0x281 0x1 ttl 0 key 00000000
key_expire: at 0
peer_clear: at 0 next 3 assoc ID 57100 refid INIT
newpeer: 10.13.1.41->10.13.2.2 mode 3 vers 4 poll 4 6 flags 0x201 0x1 ttl 0 key 00000000
local_clock: time 0 base 0.000000 offset 0.000000 freq 51.952 state 1
report_event: system event 'event_restart' (0x01) status 'sync_alarm, sync_unspec, 1 event, event_unspec' (0xc010)
refclock_transmit: at 1 127.127.1.0
refclock_receive: at 1 127.127.1.0
peer LOCAL(0) event 'event_reach' (0x84) status 'unreach, conf, 1 event, event_reach' (0x8014)
refclock_sample: n 1 offset 0.000000 disp 0.010000 jitter 0.000001
clock_filter: n 1 off 0.000000 del 0.000000 dsp 7.937500 jit 0.000001, age 0
auth_agekeys: at 1 keys 1 expired 0
timer: refresh ts 0
transmit: at 2 10.13.1.41->10.13.2.1 mode 3
receive: at 2 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
peer 10.13.2.1 event 'event_reach' (0x84) status 'unreach, conf, 1 event, event_reach' (0x8014)
clock_filter: n 1 off -0.003512 del 0.000076 dsp 7.937501 jit 0.000001, age 0
transmit: at 3 10.13.1.41->10.13.2.2 mode 3
receive: at 3 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
peer 10.13.2.2 event 'event_reach' (0x84) status 'unreach, conf, 1 event, event_reach' (0x8014)
clock_filter: n 1 off -0.016462 del 0.000136 dsp 7.937501 jit 0.000001, age 0
transmit: at 4 10.13.1.41->10.13.2.1 mode 3
receive: at 4 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 2 off -0.003512 del 0.000076 dsp 3.937516 jit 0.000001, age 2
transmit: at 5 10.13.1.41->10.13.2.2 mode 3
receive: at 5 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 2 off -0.016537 del 0.000132 dsp 3.937508 jit 0.000075, age 0
transmit: at 6 10.13.1.41->10.13.2.1 mode 3
receive: at 6 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 3 off -0.003512 del 0.000076 dsp 1.937538 jit 0.000008, age 4
transmit: at 7 10.13.1.41->10.13.2.2 mode 3
receive: at 7 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 3 off -0.016604 del 0.000129 dsp 1.937516 jit 0.000111, age 0
transmit: at 8 10.13.1.41->10.13.2.1 mode 3
receive: at 8 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 4 off -0.003512 del 0.000076 dsp 0.937565 jit 0.000011, age 6
transmit: at 9 10.13.1.41->10.13.2.2 mode 3
receive: at 9 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 4 off -0.016604 del 0.000129 dsp 0.937537 jit 0.000099, age 2
transmit: at 10 10.13.1.41->10.13.2.1 mode 3
receive: at 10 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 5 off -0.003512 del 0.000076 dsp 0.437593 jit 0.000013, age 8
transmit: at 11 10.13.1.41->10.13.2.2 mode 3
receive: at 11 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 5 off -0.016745 del 0.000128 dsp 0.437533 jit 0.000192, age 0
transmit: at 12 10.13.1.41->10.13.2.1 mode 3
receive: at 12 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 6 off -0.003512 del 0.000076 dsp 0.187620 jit 0.000015, age 10
transmit: at 13 10.13.1.41->10.13.2.2 mode 3
receive: at 13 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 6 off -0.016745 del 0.000128 dsp 0.187558 jit 0.000175, age 2
transmit: at 14 10.13.1.41->10.13.2.1 mode 3
receive: at 14 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 7 off -0.003512 del 0.000076 dsp 0.062639 jit 0.000019, age 12
transmit: at 15 10.13.1.41->10.13.2.2 mode 3
receive: at 15 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 7 off -0.016886 del 0.000129 dsp 0.062544 jit 0.000274, age 0
transmit: at 16 10.13.1.41->10.13.2.1 mode 3
receive: at 16 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 8 off -0.003512 del 0.000076 dsp 0.000167 jit 0.000020, age 14
transmit: at 17 10.13.1.41->10.13.2.2 mode 3
receive: at 17 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 8 off -0.016886 del 0.000129 dsp 0.000066 jit 0.000255, age 2
transmit: at 18 10.13.1.41->10.13.2.1 mode 3
receive: at 18 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 8 off -0.003512 del 0.000106 dsp 0.000136 jit 0.000023, age 14
transmit: at 19 10.13.1.41->10.13.2.1 mode 3
key_expire: at 19
transmit: at 19 10.13.1.41->10.13.2.2 mode 3
receive: at 19 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 8 off -0.017033 del 0.000112 dsp 0.000048 jit 0.000320, age 0
receive: at 19 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 8 off -0.003543 del 0.000110 dsp 0.000060 jit 0.000012, age 5
transmit: at 20 10.13.1.41->10.13.2.2 mode 3
key_expire: at 20
receive: at 20 10.13.1.41<-10.13.2.2 mode 4 code 1 auth 0
clock_filter: n 8 off -0.017033 del 0.000112 dsp 0.000035 jit 0.000260, age 1
transmit: at 35 10.13.1.41->10.13.2.1 mode 3
receive: at 35 10.13.1.41<-10.13.2.1 mode 4 code 1 auth 0
clock_filter: n 8 off -0.003543 del 0.000110 dsp 0.000271 jit 0.000018, age 21
0

I think the stratum on your local clock too high. It should like be at least 2 levels below the clock you want to sync to. The recommended configuration for the local clock is:

Single Time Server:

# local clock
server 127.127.1.0
fudge  127.127.1.0 stratum 10

You have:

# local clock
server 127.127.1.0
fudge 127.127.1.2 stratum 10

Your ntpq:

#ntpq -np
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*127.127.1.0     .LOCL.           5 l   63   64  377    0.000    0.000   0.001
 10.13.2.1       10.98.94.5       4 u   26   64  377    0.108   -9.741   4.278
 10.13.2.2       10.98.94.5       4 u   23   64  377    0.118  -12.981   5.226

This shows the local clock at stratum 5, not stratum 10. And since it is a perfect clock, it is used.

(Source)

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.