Why would a log file contain a * next to the date?
Why would a log file contain a * next to the date?
A log file will contain an asterisk (*) next to the date when the network device is not configured to use NTP. This indicates that the system clock has not been set by an authoritative time source, like NTP, and the date and time are likely incorrect.
C is correct. Tried in real lab with a device previously connected to NTP server : ASR1002-X#sh ntp status Clock is synchronized, stratum 4, reference is 192.168.0.12 ASR1002-X#conf t Enter configuration commands, one per line. End with CNTL/Z. ASR1002-X(config)#no ntp server 192.168.0.12 .May 13 15:02:06.514: %SYS-5-CONFIG_I: Configured from console by vty0 (10.61.104.185) So, it's not B.
I will go for C: If the system clock has not been set, the date and time are preceded by an asterisk (*) to indicate that the date and time are probably not correct.
(*) is printed when NTP is not configured on the device. (.) is printed when NTP is configured, device was once in synced, but now can't reach the NTP server. C is the correct Answer. Tested in the lab.
answer is B. If you configured NTP, but you cannot reach the NTP server, you will have the * As soon as the switch can reach the NTP server, the * will disappear. Also tested in lab
An asterisk "*" before the timestamp points to answer C as the reason. A period/dot "." before the timestamp points to answer B.
https://www.cisco.com/c/en/us/td/docs/routers/xr12000/software/xr12k_r3-9/system_management/command/reference/yr39xr12k_chapter4.html The system clock keeps an “authoritative” flag that indicates whether the time is authoritative (believed to be accurate). If the system clock has been set by a timing source, such as system calendar (CLI) or Network Time Protocol (NTP), the flag is set. If the time is not authoritative, it is used only for display. * Time is not authoritative. https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/bsm/configuration/15-2mt/bsm-time-calendar-set.html Within the CLI command syntax, the hardware clock is referred to as the system calendar.
same here: https://www.cisco.com/E-Learning/bulk/public/tac/cim/cib/using_cisco_ios_software/cmdrefs/show_clock.htm
Asterisk(*):- If the system clock has not been set, the date and time are preceded by an asterisk (*), which indicates that the date and time have not been set and should be verified. dot (.):- The dot means the router has gone out of sync with its configured NTP server and therefore the date/time may be incorrect. https://community.cisco.com/t5/switching/what-does-the-and-mean-at-the-beginning-of-a-log-buffer-entry/td-p/2494471
C is correct. At the moment of log receving the NTP was non configured. If would show a dot at the moment of log receving NTP was not in sync
I have tested it in a lab and the answer is B
Cisco IOS Configuration Fundamentals Command Reference: ASTERISK * - Time is not authoritative: the software clock is not in sync or has never been set. BLANK - Time is authoritative: the software clock is in sync or has just been set manually. DOT . - Time is authoritative, but NTP is not synchronized: the software clock was in sync, but has since lost contact with all configured NTP servers.
source: https://www.cisco.com/c/en/us/td/docs/ios/fundamentals/command/reference/cf_book/cf_s2.html#wp1486074
Answer is B. Tested in lab. I configured the NTP server and made sure the switch could reach the ntp server, no asterisk in the logs. I then rebooted the switch and looked at the logs, there was an asterisk while the switch was still coming up. Once the VLAN came up and it could reach the ntp server again, the asterisk went away.
I think D is correct. * is not related to ntp server settings at all. It just says that time was not configured by admin. As soon as I set clock manually, "*" disappeared in logs. It happens without any ntp config.
I've changed my mind. It's true that "C" is not accurate enough. "*" means that the time is not set and might be not accurate. And you can clear "*" by setting time not only using NTP but also manually. Nevertheless "D" looks even less suitable for me now. Default time stamps format would not cause "*". It's just a format after all https://community.cisco.com/t5/switching/what-does-the-and-mean-at-the-beginning-of-a-log-buffer-entry/td-p/2494471
Answer is B Check out CCIE answer https://community.cisco.com/t5/switching/what-does-the-and-mean-at-the-beginning-of-a-log-buffer-entry/td-p/2494471
B. The network device was unable to reach the NTP server when the log messages were recorded. Most accurate in lab: //刚起机，配置正确ntp但ntp没学到时间时： //When the machine is just started and ntp is configured correctly, but ntp has not learned the time: *Jan 28 02:03:50.603: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to up 000020: *Jan 28 2023 10:03:50 bj: %SYS-6-CLOCKUPDATE: System clock has been updated from 02:03:50 UTC Sat Jan 28 2023 to 10:03:50 bj Sat Jan 28 2023, configured from console by console. 000021: Jan 28 2023 10:03:51 bj: %SSH-5-DISABLED: SSH 1.99 has been disabled 000022: Jan 28 2023 10:03:55 bj: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed state to up
Answer is C. After configuring NTP server the logging * disappeared. Make sure that the time is synchronized with NTP otherwise it will still show the * on the log. R2#show ntp status Clock is synchronized, stratum 2, reference is 194.58.207.148 R2(config)#int lo0 R2(config-if)#no sh R2(config-if)#end R2# Jun 28 18:56:21.769: %SYS-5-CONFIG_I: Configured from console by console Jun 28 18:56:23.295: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed state to up Jun 28 18:56:23.296: %LINK-3-UPDOWN: Interface Loopback0, changed state to up
it's C for sure. cause when you setup a new device the logs will not have a timestamp until you use the command "service timestamps" to enable it. after you enable it if you didn't setup the time or the device is not configured with ntp server "which means in reality that the device have no time to stamp logs with it" the logs will appear with * based on this I go with C https://www.cisco.com/E-Learning/bulk/public/tac/cim/cib/using_cisco_ios_software/cmdrefs/service_timestamps.htm
If nothing is before the date, it means that your router clock was set manually or is in sync with a NTP server by the time of the log. If with an asterisk, it means you didn't set the clock or it isn't synced with a NTP server. If there's a period, it means the clock was in sync but the NTP server is not accessible. https://networkengineering.stackexchange.com/questions/10168/interpreting-cisco-logging-symbols#:~:text=If%20nothing%20is%20before%20the,synced%20with%20a%20NTP%20server.
I like B. I have a cisco switch that normally does not show * and it configured with NTP. During an issue window the * appeared in it logs.