So by playing around with Cisco Packet Tracer, I find it quite easy to create/manage networks as the whole network diagram is in front of me. I know where is what exactly.
By applying the knowledge to the real world, for example, a simple thing like VLANs, I found it very confusing to keep track of switches, VLANs and their connections to each other in a single site. The more different configurations, like VLANs and STP there are, the more difficult it becomes to keep everything in my head.
Are there any tools that network admins use to see the whole network topology in front of them so they know how exactly everything is layed out and how everything is connected together? This could vary from a single site and all of its Switches, VLANs, APs etc. to the whole view of multiple site locations and their connectivity with Routers and VPN tunnels.
Yes, it is quite useful to have the whole topology displayed as it is in reality on your computer. It gives you a better overall view of the network, and if you have the right tools, you are able to click on particular devices and see more info and even configure the devices directly from such an interface, in much the same way as you would with Packet Tracer.
There are several tools out there that have the capability of showing you your network in such a way. Ones that I have had experience with include:
The Dude, which is a nifty little piece of software that MikroTik offers (in the past it was free, I’m not sure about now). It goes through a process of network discovery and automatically creates the initial topology with all of the devices it finds. You can then add and modify it. It uses SNMP to poll devices for further information.
Whatsup Gold is similar to The Dude, but it is more sophisticated with more options and bells and whistles. It’s not free, and is typically more advanced.
LibreNMS is an autodiscovering NMS that’s free and powerful, and is web-based in its display of information. It lacks a network topology display compared to the other two, and displays most information in table format. It is still very powerful and very intuitive.
There’s a lot out there, but for the live topology view that you’re looking for, I have found that the first two are quite good options.