What are the best ways to identify network issues in real-time?

You can start with your long time best friends Ping & Traceroute 2 very simple yet very useful commands that can help you check the connectivity and latency of your network. Ping sends a packet of data to a destination and measures the time it takes to receive a response. Traceroute shows the path and the hops that the packet takes to reach the destination, along with the latency of each hop. By using ping and traceroute, you can quickly identify if there is a network outage, a routing issue, or a bottleneck in your network. Other advance monitoring tools can also be used for in depth traffic analysis: Packet sniffers NetFlow analysis SNMP monitoring Log analysis Network benchmarking Bandwidth testing

Network issues can be easily identified by starting with simple testing utilities such as pings to check for connectivity and to see response times and latency. Traceroute can help you see if there is a route missing to the destination. Telnet can be used to check if the service is reachable. When this fails, it indicates two things: permission issues or service availability issues. When a service is available but there is no recheability, it could either be a route issue or firewall permission issues. Most times in my network, it is very easy to identify network issues and separate it from application or service related issues using the above approach.

Using monitoring tools that can capture network traffic effectively is mandatory in any enterprise which help responding to any incident immediately and take critical actions. In my current job, a lot of issues and incidents minor or major have happened and we couldn’t have resolved them effectively and immediately without our monitoring tools we use and the fact that they monitor live network traffic helps a lot in resolving any issue that comes up within the network.

A well-configured NMS is central to any large network operator's toolkit. If you don't have an NMS, look at Zabbix, SolarWinds, and CheckMK, to name a few. If you leverage multiple tools and want to consolidate your network observability into a single pane of glass, consider pulling your metrics into Grafana Cloud.

GNS 3 and EVE-NG are the tools i have used. they are great tools that emulates a specific network device hardware. This are robost and can help simpulae an entire data center supposing you have the right hardware specifications to support. I use Eve-ng mostly nowadays because of it more efficeinet with resources and easy to setup. netowk chages are usally simulated, tested out in this simulate environment and then deployed to production network. A major migration that included Cisco Asa high availability and Virtual port channel was successfully completed on Eve-ng and miigrated to production .The simulation made the migration seamless for me.

Network testing provide vital information about the state of the network and tend to provide assurance of quality. from pingtests which test recahbility to a destination to speedtest , Iperf and others that that provides the idea of latency , packet loss and jilter . All these are used to understand if yur connection is good