08-13-2013 12:06 PM - edited 03-10-2019 08:46 PM
Hi,
Does any one know if ntp authentication is supported in ACS version 5.3?
08-28-2013 07:10 PM
I am not sure about ACS 5.3 but ACS 5.4 supports authenticated NTP mode. You can see the below link for release node.
08-28-2013 11:02 PM
Ravi:
What is the command to configure the NTP with authentication on ACS 5.4?
In the CLI guide for ACS 5.4 they are not mentioning anything about configuring the authentication:
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08-28-2013 10:58 PM
Hi,
No it is not. I spent sometime looking for a way to do that but I found none.
You can only configure NTP without doing any kind of auth.
Regards,
Amjad
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08-29-2013 03:34 AM
NTP Configuration on Cisco ACS
In order to synchronize the time of Cisco ACS with an NTP server, complete these steps:
NTP follows a client-server hierarchy. When an NTP client is configured with an NTP server, the Reference Clock of the NTP server is passed to the client. It takes approximately 10-20 minutes to get the accurate time from the NTP server and depends on the delay occurs in order to reach the NTP server.
Cisco ACS uses the NTP daemon in order to synchronize its clock with the NTP server. It does not support the Simple NTP, SNTP. When the NTP daemon starts, ACS sends a packet to the NTP server that contains its original time (Local). Then NTP server replies to the packet with the insertion of its Reference Clock time. Once the NTP client receives this packet, it logs the packet with its own local time in order to validate the traveling time taken by the packet. Several such packet exchanges occur in order to calculate the exact round trip delay time and offset values and finally the local time of NTP client is synchronized with the Reference Clock of the NTP server.
Verify
Use this section in order to confirm that your configuration works properly.
In order to verify the configuration details, refer to these command output snippets.
acs51/admin#show clock
Wed Jun 13 11:02:00 IST 2012
acs51/admin#
acs51/admin(config)#ntp server 192.168.26.55
The NTP server was modified.
If this action resulted in a clock modification, you must restart ACS.
acs51/admin(config)#
acs51/admin#show ntp
Primary NTP : 192.168.26.55
synchronised to NTP server (192.168.26.55) at stratum 2
time correct to within 27 ms
polling server every 64 s
remote refid st t when poll reach delay offset jitter
==============================================================================
127.127.1.0 LOCAL(0) 10 l 29 64 17 0.000 0.000 0.001
*192.168.26.55 .LOCL. 1 u 33 64 17 0.285 -9.900 2.733
Warning: Output results may conflict during periods of changing synchronization.
Note: Stratum is a measure that specifies how close is the NTP server to the Primary Reference Clock. Each NTP client that is synchronized with a stratum n server is termed as at stratum n+1 level.
Refer to these application log messages from ACS in order to verify the NTP Synchronization details.
acs51/admin# show logging application | in ntp
Jun 13 13:51:59 acs51 ntpd[20259]: ntpd 4.2.0a@1.1190-r Mon Jul 28 11:03:50 EDT 2008 (1)
Jun 13 13:51:59 acs51 ntpd[20259]: precision = 1.000 usec
Jun 13 13:51:59 acs51 ntpd[20259]: Listening on interface wildcard, 0.0.0.0#123
Jun 13 13:51:59 acs51 ntpd[20259]: Listening on interface wildcard, ::#123
Jun 13 13:51:59 acs51 ntpd[20259]: Listening on interface lo, 127.0.0.1#123
Jun 13 13:51:59 acs51 ntpd[20259]: Listening on interface eth0, 192.168.26.51#123
Jun 13 13:51:59 acs51 ntpd[20259]: kernel time sync status 0040
Jun 13 13:51:59 acs51 ntpd[20259]: frequency initialized 0.000 PPM from /var/lib/ntp/drift
Jun 13 13:51:59 acs51 ntpd: ntpd startup succeeded
Jun 13 13:55:15 acs51 ntpd[20259]: synchronized to 192.168.26.55, stratum 2
!--- Output suppressed–
The Output Interpreter Tool (registered customers only) (OIT) supports certain show commands. Use the OIT to view an analysis of show command output.
Troubleshoot
This section provides information you can use to troubleshoot your configuration.
Problem: Clock drifts too much and NTP fails when ACS is installed on a VMWare machine
Cisco ACS is configured to use the NTP server as the clock source but it continually changes to the internal time source. When this happens, it does notallow users to authenticate from Active Directory as Kerberos only supports 300 seconds of time difference.
Solution
When the ESXi host has high CPU utilization, then it does not serve VMs as frequently as normal. This affects the clocks inside VMs and actually cause clock drift from a Windows Domain Controller that exceeds five minutes. It causes the Kerberos to fail. This would impact a Windows VM without NTP or host clock sync as well. As the virtual clock presented to Cisco ACS is not stable enough for NTP to keep up with the drift, it eventually reverts to using itself as a time source.
Note: The NTP daemon adjusts the clock in several exchanges and continues until the client obtain the accurate time. However, when the delay between NTP Server and the NTP Client become too big, then the NTP daemon gets terminated and you need to adjust the time manually and re-start the NTP daemon.
This problem is set to be resolved when you integrate the VMWare tools support into Cisco ACS, which is available with Cisco ACS release 5.4 that is yet to be released. Refer to Cisco bug ID CSCtg50048 (registered customers only) for more information. As a temporary workaround, you could try these steps:
Note: If these steps do not resolve the issue, you are advised to contact Cisco TAC.
NTP Synchronization lost after the interface IP address of ACS is changed
If you change the IP address of ACS NIC, this makes the NTP go out of sync.
Solution
This behavior is observed and logged in Cisco bug ID CSCtk76151 (registered customers only) . When the ACS IP address is modified, it restarts the ACS application but not the NTP daemon. It is fixed in ACS version 5.3.0.23. In order to resolve this issue in prior versions, complete these steps:
Note:
For more information please visit:
http://www.cisco.com/en/US/products/ps9911/products_configuration_example09186a0080bc612b.shtml
08-29-2013 03:39 AM
Ok Aqeel and how can all that long text answer the answer? it does not really do.
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08-29-2013 04:18 AM
No, it's not supported in ACS 5.3. It was added in ACS 5.4
System Operations Enhancements
Network Time Protocol (NTP)
ACS 5.4 supports authenticated NTP mode and the existing nonauthenticated NTP mode.
~BR
Jatin Katyal
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