Essential knowledge that isn't so essential to all admins.

As the headline suggests, I'm going to talk about Knowledge that isn't so common to everyone of us. Atleast that's what it seems like to me. A short background info on why I am writing this today.

I had to troubleshoot our network today because one of my colleagues told me that he can't reach the server. After I asked him what he already tried to troubleshoot, he told me "nothing, I can't reach it".
It ended up being a DNS problem. It's always DNS!

But that moment got me thinking and I thought that there might be knowledge we take as common that is not as common as we think it is. The topic I'm talking about is Networking.

Networking is essential in my opinion because if there are no roads, how are you going to get moving? There are quite a few guys I've talked to which were familiar with their applications and a special OS like Windows Server but they just knew the very basics of networking such as routing and switching, vlans and trunks. So what I want to say is: train yourself to understand networking, the basics of routing and how the networks you are sitting in are working. But that's not all of course.

Once a colleague called me because he had to install a video conference system and it would not be able to communicate with our network. So after checking all the cables we went to the IP-Configuration where the problem was hiding. Subnetting which also belongs to networking. The conference system had the network address configured as the ip address ... not a big deal, it was fixed within a few seconds but the concept of subnetting was new to my colleague which installed it.

Quick explaination what I am talking about:

A typical Network has the following addresses assuming we are working with a /24-bit Subnetmask (255.255.255.0).

172.31.10.0 => This one finds usage in routing (for example) and is called the 'network address' and is not usable for computers, mobile devices, printers, TVs or anything else that is connected to a network.

172.31.10.1 - 172.31.10.254 => Addresses that can be assigned to endpoint devices to talk to each other, Usually a range is reserved for the dhcp server which hands out the ip addresses and additional information such as gateway and netmask to the client if a request was submitted.

172.31.10.255 => The broadcast address of the network which also cannot be used for end devices.
The name already tells what it is used for. Staying with the DHCP-Example, a dhcp request goes to the address 255.255.255.255 and the dhcp-server responds handing out network informations to the client.

So that's it for the beginning. Thanks for staying with me and feel free to comment.

Comments

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