Network routing for managers
Introduction
This article will try to explain in manager language with as example the logistics process inside an organisation how network routing works in the basis. This is always very helpfully for me to explain my manager how networking and routing works if we encounter problems on this specific network part.
Logistic process
Network routing can be seen as a logistic process inside a company. By default we have a logistics partner who is sending our packages around the world. We have a really good deal with them but for some countries we have found other suppliers with betters deal.
Example: Our default carrier is DHL . They have good shipping rates except for big boxes we have to send to China. They are too slow, therefore we spoke to UPS and they offered us a deal which saves us 20% on shipping costs to China. This sounds very cool uh? But the process changes inside the company. Default: DHL. Big boxes to China: UPS.
Networks connected
As you could see in the example we have two routes. One default and one for a specific reason. This is also the same for servers inside a network. We have a default gateway (DHL) but for one specific service we need to use another gateway (UPS). This is where routing could be compared to logistic transport.
Server example: We have a server called web01. Default is should connect to the internet, but for our connection to the database we should connect to the database network. The database network is in the following subnet: 10.73.162.0/24. The webserver is connected to two networks. The internet (123.123.123.1 as gateway) and the internal network (10.74.17.1 as gateway to the databases).
Connections to the internet should go through our default gateway, 123.123.123.1. BUT here is the catch. We should have a line in our routing table (logistical policy when we are refering to the logistics process inside a company). This line will say. All traffic to the 10.73.162.0/24 network should go through the network router 10.74.17.1.
With that line our webserver will now where to awnser to if we receive data or need to request data from the database server. Not throught its default gateway connected to the internet. But throught the network router which will help us connecting to the database servers.
Summary
As you can see. Network routers are an important part of the infrastructure. Basically they are cariers between networks. Before we know where we should send our package to we have to read the company policy of which carier we should select. Routing tables are essentially the companies carier policy.