Enabling SNMPv2c on a Cisco Router, for example.

configure terminal
snmp-server community PASSWORD_STRING ro
snmp-server community PASSWORD_STRING rw

Now you can use any tool to monitor and manage your device, such as ManageEngine MibBrowser Free Tool [Link].

For monitor applications, there are big players such as OpenNMS [Link], Zabbix [Link], Nagios [Link], SolarWinds, Airwave, PRTG, etc.

The SYSLOG centralizes the log of the network devices in a server.

After setting up the server SYSLOG server, for example, Kiwi Syslog Server Free Edition from SolarWinds [Link], set up the network devices to sent log information to the server.

clock set 13:45:00 02 Mar 2021
configure terminal
service timestamps log datetime msec
logging trap informational

Staring the process of setting the clock is a good practice to prevent sending logs to the server that will make the debugging very confusing.