Enabling SNMPv2c on a Cisco Router, for example:
enable configure terminal snmp-server community PASSWORD_STRING ro snmp-server community PASSWORD_STRING rw
You can then use any tool to monitor and manage your device, such as ManageEngine MibBrowser Free Tool [Link].
For monitoring applications, popular options include OpenNMS [Link], Zabbix [Link], Nagios [Link], SolarWinds, Airwave, PRTG, and others.
SYSLOG centralizes log collection from network devices into a single server.
After setting up a Syslog server (for example, Kiwi Syslog Server Free Edition by SolarWinds [Link]), configure your network devices to send log information to it:
enable clock set 13:45:00 02 Mar 2021 configure terminal service timestamps log datetime msec logging 10.0.0.254 logging trap informational
Setting the clock first is good practice, as incorrect timestamps can make log debugging confusing.