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Syslog:
In computing, syslog is a standard for message logging. It allows separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them. Each message is labeled with a facility code, indicating the software type generating the message, and assigned a severity label.
Computer system designers may use syslog for system management and security auditing as well as general informational, analysis, and debugging messages. A wide variety of devices, such as printers, routers, and message receivers across many platforms use the syslog standard. This permits the consolidation of logging data from different types of systems in a central repository. Implementations of syslog exist for many operating systems.
NTP:
Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks. In operation since before 1985, NTP is one of the oldest Internet protocols in current use. NTP was designed by David L. Mills of the University of Delaware.
NTP is intended to synchronize all participating computers to within a few milliseconds of Coordinated Universal Time (UTC). It uses the intersection algorithm, a modified version of Marzullo’s algorithm, to select accurate time servers and is designed to mitigate the effects of variable network latency. NTP can usually maintain time to within tens of milliseconds over the public Internet, and can achieve better than one millisecond accuracy in local area networks under ideal conditions. Asymmetric routes and network congestion can cause errors of 100 ms or more.
The protocol is usually described in terms of a client-server model, but can as easily be used in peer-to-peer relationships where both peers consider the other to be a potential time source. Implementations send and receive timestamps using the User Datagram Protocol (UDP) on port number 123.[4][5] They can also use broadcasting or multicasting, where clients passively listen to time updates after an initial round-trip calibrating exchange. NTP supplies a warning of any impending leap second adjustment, but no information about local time zones or daylight saving time is transmitted.
The current protocol is version 4 (NTPv4), which is a proposed standard as documented in RFC 5905. It is backward compatible with version 3, specified in RFC 1305
Transcription:
The first thing I need to do is configure the NTP server.
So on the NTP server, go to NTP and I’ll enable the NTP service.
I’m not going enable authentication at this point. I can then specify the date and time.
This is okay for this lab. The clock on the local PC is the 12th of April 2018; time is 4:38 am.
We’re told to check the time on the router and the switch first.
At the moment show clock
shows us that the router thinks it’s in 1993. The switch thinks it’s also 1993. So the time is wrong on both these devices.
Before we configure NTP, let’s send timestamp messages to the syslog server.
So at the moment, the syslog server is not showing timestamps on syslog messages.
So on the router, I’m going to type
service timestamps log messages date and time and milliseconds
Notice the difference now when I type end
we can see the date and time on the syslog message.
But it’s the wrong date and time. So that doesn’t really help us with troubleshooting. We want to know when something took place.
So we want date and time as well as milliseconds.
But again, the switch as showing the wrong date and time.
So we need to fix that, so, on the router
ntp server
We need to specify the IP address of the NTP server; NTP server has this IP address 10.1.1.201
So specify IP address of NTP server. When I type end now and press Enter. Notice the correct date and time is displayed on the syslog message.
It’s the 12th of April 2018, the time is 4:42 am.
So that’s good.
Configure the switch, so ntp server 10.1.1.201 type end
Notice the correct date and time is displayed. We’re getting messages from both the router and the switch. We’re told to verify the date and time on the router and the switch.
So on the router show clock
shows the correct date and time.
