For years, radial network maps were the most commonly-used layout for handling data.
However, as most tech industry aficionados can attest, “most common” does not necessarily mean “the best.” For example, radial network maps are great for very high-level drawings. However, the map does not follow a logical layout or show the path used to move traffic to and from the Internet. Sure, the maps are great at filling white space and displaying more network devices. Still, whether you zoom in or out, there just isn’t any logical flow.
The route-driven hierarchical network map, on the other hand, is very different. As the name implies, it uses IP routing to determine where devices appear in the hierarchy. The network path is based on Layer 3 routing and Layer 2 switching protocols, and the default flow for this layout is top to bottom.
bitB maps are Internet-driven.
This means they use Layer 3 routing to display the paths used to move edge device traffic such as users, servers, etc., to and from the internet. Simultaneously, they display the path of network traffic as it would flow from devices on the internal network to the internet. As you can see in the above image, there is an internet cloud at the top of the drawing to demonstrate the connection between the internet provider’s device and the on-premises network.
This device is created dynamically based on the next-hop IP address of the default route for the on-premises Layer 3 device that is closest to the Internet. The same process of identifying this device is used for all subsequent devices in the network. This means that bitB will look at each device with a default route, then display the subnet for the next-hop IP address. Afterward, bitB will add the next-hop device to the map and continue the process until the entire map is completed.
As an added benefit, there are also different topology themes. These are used to determine which subnets and routes are to be displayed on the map. Currently, bitB supports two such themes: All Subnets and Interconnect Subnets. The former is great when you’re looking for details in a specific area of your network, as it will be helpful to see all the respective subnets.
However, when you want to see the paths taken by transit traffic through the various network devices, you don’t want to display those subnets that don’t participate. Luckily, you can simply remove two types of subnets from the drawing.
- Edge Device Subnets (end-user, server, etc.)
- Out of Band Management Subnets
These subnets are rarely the destination for a default route, so adding them will only end up cluttering the map. Fortunately, when this happens, you can select “Interconnect Subnets.” In the image to the left, you can see a route-driven hierarchical network map displaying all subnets. Call-out #1 shows the management network subnet in detail. As you can see, there are many device connections. However, none of them move users or server traffic to or from the internet. When you’re troubleshooting, knowing which devices and paths perform this function is very important. Fortunately, by removing the unneeded subnets, you can clean up the drawing and reveal the visuals needed to understand this path. You can see this demonstrated in the image on the right.
With bitB, you also have the power to change the layout direction of the map.
As I stated, the default direction is top to bottom. However, with the click of a button, you can cause it to flow left to right, right to left, or bottom to top.
Route-driven hierarchical network maps are also used for Physical and vPhysical mapping. In these cases, the placement of the device in the physical drawing hierarchy will be determined by the default route of that device. This is the same procedure used to determine the location in the Logical map. It can be most easily seen when you have a vPhysical or Physical map that includes the switch connecting the firewall to the Internet. In such cases, the switch will be displayed above the firewall and will be determined by the Layer 3 default routes, IP ARP tables, and Layer 2 MAC address tables.
As you can see, the route-driven hierarchical network map can prove extremely valuable when troubleshooting networks. So, don’t spend your time running in circles with the radial network map when there’s a better option. With the route-driven hierarchical network map, you can visualize the path network devices use to route and switch packets far more easily.