I'm using the ntp package in debian squeeze and the ntpd process is listening on hundreds of rfc1918 addresses that are not configured on the server.

Check this out:

Mar 26 10:07:24 server ntpd[14701]: ntpd 4.2.6p2@1.2194-o Sun Oct 17 13:45:13 UTC 2010 (1)
Mar 26 10:07:24 server ntpd[14702]: proto: precision = 0.986 usec
Mar 26 10:07:24 server ntpd[14702]: Listen and drop on 0 v4wildcard 0.0.0.0 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen and drop on 1 v6wildcard :: UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 2 lo 127.0.0.1 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 3 eth0 66.xxx.xxx.xxx UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 4 eth0 192.168.1.1 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 5 eth0 192.168.1.2 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 6 eth0 192.168.1.3 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 7 eth0 192.168.1.4 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 8 eth0 192.168.1.5 UDP 123
...
...
...
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 499 eth0 192.168.2.240 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 500 eth0 192.168.2.241 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 501 eth0 192.168.2.242 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 502 eth0 192.168.2.243 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 503 eth0 192.168.2.244 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 504 tun0 10.13.37.1 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 505 tun1 10.13.42.2 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 506 lo ::1 UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 507 eth0 2600:xxxx::xxxx UDP 123
Mar 26 10:07:24 server ntpd[14702]: Listen normally on 508 eth0 fe80::xxxx UDP 123

My configuration file:

driftfile /var/lib/ntp/ntp.drift
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
server 0.debian.pool.ntp.org iburst
server 1.debian.pool.ntp.org iburst
server 2.debian.pool.ntp.org iburst
server 3.debian.pool.ntp.org iburst
restrict -4 default kod notrap nomodify nopeer noquery
restrict -6 default kod notrap nomodify nopeer noquery
restrict 127.0.0.1
restrict ::1

ifconfig eth0:

eth0 Link encap:Ethernet HWaddr f2:xx:xx:xx:xx:xx
inet addr:66.xxx.xxx.xxx Bcast:66.xxx.xxx.xxx Mask:255.255.255.0
inet6 addr: 2600:xxxx::xxxx/64 Scope:Global
inet6 addr: fe80::xxxx/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:69898198 errors:0 dropped:0 overruns:0 frame:0
TX packets:55539406 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:25263193357 (23.5 GiB) TX bytes:41787470527 (38.9 GiB)
Interrupt:76

Any ideas why?

  • Did you paste the full output of ifconfig -a ? How is ntp listening on tun0 and tun1 if you do not have those devices configured? – dfc Mar 26 '14 at 14:56
  • That's just ifconfig eth0. ifconfig -a doesn't have any references to 192.168.anything, but I can post it if there could be value in having it. – cpugeniusmv Mar 26 '14 at 15:18
up vote 1 down vote accepted

I don't have the full output pre-grep because my scrollbuffer filled up, but:

# ip addr show dev eth0 |grep 192.168.[12]
inet 192.168.1.1/16 scope global eth0
inet 192.168.1.2/16 scope global secondary eth0
inet 192.168.1.3/16 scope global secondary eth0
inet 192.168.1.4/16 scope global secondary eth0
inet 192.168.1.5/16 scope global secondary eth0
...

And this solved it:

ip addr del 192.168.1.1/16 dev eth0

It was most likely a side-effect of some fiddling I was doing with openvpn configurations a while back.

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