I had a similar instance on wheezy, twice on the same machine. the machine has many GRE interfaces, for each of them /etc/network/if- up.d/ntpdate runs ntpdate, and each take 15-20s. thanks to a lockfile mechanism, each instance of this script is run sequentially, so they are all able to use the NTP socket.
when ntpd is finally launched, the last ntpdate[10802] is probably still running, then ntpd finds the socket already bound and fails to start. /etc/network/if-up.d/ntpdate and /etc/init.d/ntp apparently use a lockfile to prevent this. I tested it by starting /etc/network/if- up.d/ntpdate and /etc/init.d/ntp in parallel, and it seeems to work: /etc/init.d/ntp blocks waiting for the lockfile to clear and then starts successfully. but apparently it does not work at boot (failed to start ntpd 2 out of 2 reboots) MAtteo 09:07:21 HOSTNAME kernel: [ 9.641010] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None 09:07:21 HOSTNAME kernel: [ 9.766666] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 9.795365] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 9.819803] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 9.845117] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 9.869878] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 9.894190] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 9.918750] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 9.943501] ipv6: addrconf_gre_config(gre_) 09:07:21 HOSTNAME kernel: [ 11.016141] ip_tables: (C) 2000-2006 Netfilter Core Team 09:07:21 HOSTNAME kernel: [ 11.029841] nf_conntrack version 0.5.0 (16384 buckets, 65536 max) 09:07:21 HOSTNAME kernel: [ 11.410229] ip6_tables: (C) 2000-2006 Netfilter Core Team 09:07:27 HOSTNAME kernel: [ 13.707481] device eth0 entered promiscuous mode 09:07:33 HOSTNAME kernel: [ 20.384946] eth0: no IPv6 routers present 09:07:34 HOSTNAME ntpdate[1722]: step time server 203.159.70.33 offset -0.006063 sec 09:07:49 HOSTNAME ntpdate[3306]: adjust time server 203.159.70.33 offset 0.000123 sec 09:08:04 HOSTNAME ntpdate[3368]: adjust time server 203.159.70.33 offset 0.000171 sec 09:08:24 HOSTNAME ntpdate[4947]: adjust time server 203.159.70.33 offset 0.000046 sec 09:08:49 HOSTNAME ntpdate[4967]: adjust time server 203.159.70.33 offset 0.000252 sec 09:09:19 HOSTNAME ntpdate[4997]: adjust time server 203.159.70.33 offset 0.000339 sec 09:09:54 HOSTNAME ntpdate[6570]: adjust time server 203.159.70.33 offset 0.000271 sec 09:10:35 HOSTNAME ntpdate[8935]: adjust time server 203.159.70.33 offset 0.000336 sec 09:11:13 HOSTNAME ntpd[10818]: ntpd [email protected] Wed Oct 28 20:18:41 UTC 2015 (1) 09:11:13 HOSTNAME ntpd[10819]: proto: precision = 0.160 usec 09:11:13 HOSTNAME ntpd[10819]: unable to bind to wildcard address 0.0.0.0 - another process may be running - EXITING 09:11:19 HOSTNAME ntpdate[10802]: adjust time server 203.159.70.33 offset 0.000376 sec
