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FUBAR

Member

From: Belgium

Registered: 2004-12-08

Posts: 1,029

Website

OpenNTPd doesn't except incoming connections

Here's something strange: while I was installing my router I added OpenNTPd as a service for the LAN. I edited the config file and I guess I didn't pay close enough attention because apparently none of the boxes on the LAN are able to sync their system clock using the router as time server.

I've been investigating it, and here's what I've come up:

1. the firewall is set up to allow traffic from the LAN to the firewall on the NTP port (123)

[20:59:46] root@accalia:/etc/shorewall # shorewall show | grep 123
   30  2280 ACCEPT     udp  --  *      *       0.0.0.0/0            0.0.0.0/0           udp dpt:123

2. my /etc/hosts.allow is configured

sshd sshd1 sshd2 :      ALL                             :       ALLOW
ntp              :      ALL                             :       ALLOW

I was using "10.0.0.0/255.255.255.240" first, but I changed it to ALL to make sure.

3. OpenNTPd is configured properly:

listen on 10.0.0.1
servers pool.ntp.org

4. OpenNTPd is running and actually listening for connections!

[21:05:58] root@accalia:/etc/shorewall # netstat -l | grep ntp
udp        0      0 accalia.begaaid.be:ntp  *:*

So everything should be OK, right? WRONG! When I try to sync the clock of one of the systems on the LAN I get an error:

[21:17:43] root@venetia:/ $ ntpdate accalia.begaaid.be
26 May 21:17:44 ntpdate[27366]: no server suitable for synchronization found

And when I port probe the server, nmap tells me port 123 is closed.

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A bus station is where a bus stops.
A train station is where a train stops.
On my desk I have a workstation.

cactus

Taco Eater

From: t͈̫̹ͨa͖͕͎̱͈ͨ͆ć̥̖̝o̫̫̼s͈̭̱̞͍̃!̰

Registered: 2004-05-25

Posts: 4,622

Website

Re: OpenNTPd doesn't except incoming connections

you probing by ip or by domain name. if by domain..make sure that the domain resolves appropriately.

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"tacos" -- Cactus' Law
"t̥͍͎̪̪͗a̴̻̩͈͚ͨc̠o̩̙͈ͫͅs͙͎̙͊ ͔͇̫̜t͎̳̀a̜̞̗ͩc̗͍͚o̲̯̿s̖̣̤̙͌ ̖̜̈ț̰̫͓ạ̪͖̳c̲͎͕̰̯̃̈o͉ͅs̪ͪ ̜̻̖̜͕" -- -̖͚̫̙̓-̺̠͇ͤ̃ ̜̪̜ͯZ͔̗̭̞ͪA̝͈̙͖̩L͉̠̺͓G̙̞̦͖O̳̗͍

FUBAR

Member

From: Belgium

Registered: 2004-12-08

Posts: 1,029

Website

Re: OpenNTPd doesn't except incoming connections

I used both. Now, it seems that sometimes my requests do get through but sometimes they don't. This is very peculiar.

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A bus station is where a bus stops.
A train station is where a train stops.
On my desk I have a workstation.