root@OpenWrt-R5:~# uci show system | grep ntp
system.ntp=timeserver
system.ntp.enabled='1'
system.ntp.enable_server='0'
system.ntp.server='0.openwrt.pool.ntp.org' '1.openwrt.pool.ntp.org' '2.openwrt.pool.ntp.org' '3.openwrt.pool.ntp.org'
root@OpenWrt-R5:~# netstat -lnp | grep ntp
root@OpenWrt-R5:~# ./pstree.sh
1 /sbin/procd
|- 1811 /sbin/ubusd
|- 1812 /sbin/askfirst /usr/libexec/login.sh
|- 1813 /bin/ash --login
|- 2041 /sbin/logd -S 64
|- 2072 /sbin/rpcd -s /var/run/ubus.sock -t 30
|- 2135 /usr/sbin/dnsmasq -C /var/etc/dnsmasq.conf.cfg01411c -k -x /var/run/dnsmasq/dnsmasq.cfg01411c.pid
|- 2168 /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
| |- 2599 /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
| | L- 2600 -bash
| L- 2715 /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
| L- 2716 -bash
| L- 2913 /bin/sh ./pstree.sh
|- 2223 /sbin/netifd
| |- 2478 /bin/sh /sbin/hotplug-call iface
| | L- 2518 /bin/sh /sbin/hotplug-call iface
| | L- 2526 /usr/sbin/ntpclient -c 1 -p 123 -i 2 -h 0.openwrt.pool.ntp.org
| L- 2493 udhcpc -p /var/run/udhcpc-br-lan.pid -s /lib/netifd/dhcp.script -f -t 0 -i br-lan -x hostname:OpenWrt-R5 -C -O 121
|- 2260 /usr/sbin/odhcpd
|- 2320 /usr/sbin/uhttpd -f -h /www -r OpenWrt-R5 -x /cgi-bin -t 60 -T 30 -k 20 -A 1 -n 3 -N 100 -R -p 0.0.0.0:80 -p [::]:80
L- 2641 /usr/sbin/ntpd -n -N -S /usr/sbin/ntpd-hotplug -p 0.openwrt.pool.ntp.org -p 1.openwrt.pool.ntp.org -p 2.openwrt.pool.ntp.org -p 3.openwrt.pool.ntp.org
root@OpenWrt-R5:~# kill 2526
After that it did execute the firewall hotplug script,
[ 249.441107] sbin-hotplugcall-122148 iface
[ 249.456593] sbin-hotplugcall-122148 firewall
[ 249.458356] sbin-hotplugcall-122148 firewall NODIR-/etc/hotplug.d/firewall
but this does not happen all the time I run the kill command.
root@OpenWrt-R5:~# ./pstree.sh
1 /sbin/procd
|- 1811 /sbin/ubusd
|- 1812 /sbin/askfirst /usr/libexec/login.sh
|- 1813 /bin/ash --login
|- 2041 /sbin/logd -S 64
|- 2072 /sbin/rpcd -s /var/run/ubus.sock -t 30
|- 2135 /usr/sbin/dnsmasq -C /var/etc/dnsmasq.conf.cfg01411c -k -x /var/run/dnsmasq/dnsmasq.cfg01411c.pid
|- 2168 /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
| |- 2599 /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
| | L- 2600 -bash
| L- 2715 /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
| L- 2716 -bash
| L- 3308 /bin/sh ./pstree.sh
|- 2223 /sbin/netifd
| L- 2493 udhcpc -p /var/run/udhcpc-br-lan.pid -s /lib/netifd/dhcp.script -f -t 0 -i br-lan -x hostname:OpenWrt-R5 -C -O 121
|- 2260 /usr/sbin/odhcpd
|- 2320 /usr/sbin/uhttpd -f -h /www -r OpenWrt-R5 -x /cgi-bin -t 60 -T 30 -k 20 -A 1 -n 3 -N 100 -R -p 0.0.0.0:80 -p [::]:80
|- 2641 /usr/sbin/ntpd -n -N -S /usr/sbin/ntpd-hotplug -p 0.openwrt.pool.ntp.org -p 1.openwrt.pool.ntp.org -p 2.openwrt.pool.ntp.org -p 3.openwrt.pool.ntp.org
L- 3101 /usr/sbin/ntpclient -i 600 -s -l -D -p 123 -h 1.openwrt.pool.ntp.org
After I have killed all the ntpclients
root@OpenWrt-R5:~# netstat -lnp | grep ntp
udp 0 0 0.0.0.0:49476 0.0.0.0:* 2640/ntpd
root@OpenWrt-R5:~# /usr/sbin/ntpclient -c 1 -p 123 -i 2 -h 0.openwrt.pool.ntp.org
44013 45069.716 11032.0 66.1 3724.2 24566.7 0
root@OpenWrt-R5:~# /usr/sbin/ntpclient -c 1 -p 123 -i 2 -h 0.openwrt.pool.ntp.org
The second call hangs, I have to cancel it via Ctl+c.
If I call it a couple times in a row, then it stucks and this is probably what happens in the hotplug script and what causes the issue.
In general, for what is the ntpclient actually required?
So far as I have seen has the OpenWRT system 19.07.3 an ntp client already included.
I did setup my router with a setup script created a couple years ago, maybe was ntp not included in older versions of OpenWRT and this is the reason why the script installs ntpclient?
It does not help to set system.ntp.enabled='0', means it is not a problem to run both at the same time. Even if I kill all ntp processes and if I start a couple ntpclient commands in a row, then it stucks.
So what is then wrong with the ntpclient command that causes it to stuck?