Technical Helpweb

Symptom:

Dialogic® IMG 1010 Integrated Media Gateway (IMG 1010) does not synchronize to the SNTP server, but the SNTP server is already synchronized to an NTP time server.

The SNTP server is on Red Hat Enterprise Linux (RHEL) 4; the issue does not occur on RHEL 3.

Reason for the issue:

The behavior of NOTRUST changed between NTP versions 4.1 (used by RHEL 3) and 4.2 (used by RHEL 4):
• In 4.1 (and earlier) NOTRUST means "Don't trust this host/subnet for time".
• In 4.2 (and later) NOTRUST means "Ignore all NTP packets that are not cryptographically authenticated". 

The behavior in version 4.2 (and later) forces remote time servers to authenticate themselves to a client ntpd.

For more information please refer to the NTP Public Services Project Website http://support.ntp.org/bin/view/Support/TroubleshootingNTP#Section_9.7.

To check the NTP version, run the program ntpdc in the /usr/sbin directory: 

ntpdc
ntpdc> version
ntpdc 4.2.0a@1.1190-r Mon Oct 11 09:10:23 EDT 2004 (1)
ntpdc>

Alternatively, you can run rpm to check the NTP version: 

$ rpm -qa | grep ntp-
ntp-4.2.0.a.20040617-4

Fix / Solution:

Edit the ntp.conf to configure the SNTP server:

1. Open a terminal session on the Linux system and Login as root

2. Edit the ntp.conf file:
 

vi /etc/ntp.conf 

3. Remove notrust from the line containing the IP address of the IMG 1010.
 

restrict 10.129.45.150 mask 255.255.255.224 nomodify notrap

4. Save the file. 

 

Alternatively, run the ntp configuration script with optional parameter rh4: (located at opt/cantata/common/osconfig).
 

 ./xlntp rh4

Restart the SNTP server:  

service ntpd restart

 

Verify the Linux system is synchronized with an NTP server: 

 ntpstat 

Verify the correct time on the IMG 1010 using the front panel, or via a telnet terminal session on the IMG 1010, typing the b command: 

>b

….
System Time: TUE, MAR 04 2008 17:14:30 UTC
….

Product List

Dialogic® IMG 1010 Integrated Media Gateway


Glossary of Acronyms / Terms

NTP: Network Time Protocol
SNTP: Simple Network Time Protocol