What should a novice network administrator know and be able to do?

Question

Computer networks

Good afternoon. At the moment, I am preparing myself for the CCNA (August this year). I work as an assistant system administrator, I don’t have enough knowledge, but I don’t want to remain an eternal enikey worker.
I'm planning to switch to networking.
Based on the question about the skills of the system administrator, I ask you to help with the skills for the network administrator. I looked through the vacancies, but there is little understanding. Thank you. =)

Answer 1

0) Let's imagine that it is necessary to transfer data between computers 1 and 2. No Ethernet and IP have yet been invented, let's say. There are wires, optical fiber, appropriate transceivers. What to do? (seven-level model and why it is not a sacred cow, multiplexing, encapsulation)
1) Switching. How is traffic processed (redirected) by the switch? Suppose a frame arrives with such and such a source address and such and such a destination address - what happens? What and why will happen if two 'wooden' (without STP and other frills) switches are connected by two links? How to deal with this (STP, what are the disadvantages)?
2) IPv4 static routing. Why is IP needed at all when there are Ethernet or Serial interfaces (although, in my opinion, IP appeared earlier than Ethernet, but the question has a certain meaning, intersects with point 0)? Suppose a packet arrives at the router (more precisely, an Ethernet frame with an IP packet in it). What happens next? What is the conceptual difference between packet redirection at 3 and 2 levels of EMOS? Why is an l2 loop (in the case of Ethernet) a gnashing of teeth, but an L3 loop is not so scary? What is the conceptual difference between IPv4 addresses and MAC addresses?
3) How to make Ethernet and IP work together (this is about ARP)?
4) Draw a router-on-a-stick topology where a router routes traffic between two vlans. A switch is connected to it by a trunk, two hosts in different vlans are connected to the switch. One host sends an icmp echo request to another ('pings'). What happens on each device? What addresses (IP, MAC) are used in packet and frame headers at different stages? What is the content of the routing, switching, ARP tables?
5) Already after a clear mastery of the above: security (ACL, firewalls), tunnels (why are they needed, what are the disadvantages), NAT (why are they needed, what are the disadvantages). dynamic routing. How the Internet works (and how the Internet differs from the Worldwide web)
From books, Jeff Doyle, 'Routing TCP/IP', volume I, first few chapters. And there is a good book ., on the topic of 'what was not said in the CCNA course'.
Gave the most basic questions. Having dealt with them, I think you yourself will be able to set the further vector of development.

Answer 2

And here you are, on the toaster, look at the questions from the network sections, network administration. See what people face and what skills are needed)

Answer 3

linkmeup.ru/blog/11.html