How to get started with cisco?

Question

Cisco

Tell a beginner where to start acquaintance with ciscos?
I must say right away that I started reading all sorts of different books, and almost always stopped at the same thing - the "classification" of ciscos - for some reason I didn’t find a direct indication anywhere, they say ASR, ISR are routers, Catalyst is also a router, and XR too (and what is the difference between them is not explained) ...
- what is a "cloud router"?
- again, where can you more or less learn about the differences between the series?
- How is a perimeter router different from just a router? - for example, there was an article
recently , based on which it is not clear to me what a firewall and an intrusion prevention system are, because in my head is it all equivalent to a firewall and is built into the router?
- and other questions that are not very smart ...
so, where to start, so that such questions would decrease? Relatively speaking, I would like to know something, thanks to which, seeing the name of the piece of iron, I could understand what it is and what it is for, and what is the difference from the rest (at this stage)

Answer 1

I'll tell you a secret - there are no switches, routers, firewalls and so on. There are devices. Each device has a specific functionality. Example:
Next, for your questions:

- what is a "cloud router"?

Almost any phrase containing the word "cloudy" (except "cloudy weather") is the fruit of a gloomy marketing genius. I don't know what a "cloud router" is. This could mean "SOHO router with built-in file cloud client". This may mean "a group of routers with centralized management / automatic distribution (provisioning) of resources to end users", a step towards SDN (software-defined networking). It can mean anything, it's a marketing term.

- again, where can you more or less learn about the differences between the series?

The most logical thing is on the cisco.com website . Also, in my opinion, there were overview videos on the skillfactory youtube channel.

- How is a perimeter router different from just a router?

Position in the network topology (on the border of your network and your provider's network) and the requirements arising from this (EBGP sessions, some kind of traffic filtering, etc.).

- for example, there was an article recently, based on which it is not clear to me what a firewall and an intrusion prevention system are, because in my head is it all equivalent to a firewall and is built into the router?

Firewalls, as far as I know, started out as simple packet filters, then session stateful filters (TCP), then L7 data filters (Application level gateways, ALG; it started with the need to handle the FTP protocol, known for its specific design), then added antiviruses, antispam and search for signatures of malicious traffic (IDS / IPS). Often all these features are combined to one degree or another in one device (Unified Threat Management, UTM).

So, where to start to reduce such questions?

Review the specifications and use cases for each of the device families you are interested in. Understand what features of the devices (large memory capacity - you can accept several BGP Full View, high-performance ASICs - low delays in traffic processing, cryptographic accelerator - high performance of encrypted tunnels, etc.) allow you to use them in their respective roles.

Answer 2

The purpose of the Cisco courses is to give a general idea, a base. After them, you will find out how the l2 switch, l3 switch, and router differ. They will not tell you how, say, 3560 differs from 3750. Only by reading the specifications of devices, all sorts of compare products, it will be possible to understand how they differ. But again, in order to understand what is written there, it is desirable to know the "mat. part", the same Cisco courses.
Further, it is important to understand that there are different classes of devices. For example, Cisco ASR 1006 and some 2901 are both routers, but the first one is for providers, and the second one is for not very large companies, the functionality is appropriate.
In addition, device capabilities may differ even within the same model due to firmware versions or activated license.
All this information can be obtained from the Cisco website (preferably only English articles), and it is desirable, if possible, to attend Cisco Expo.
For your specific questions:
Abbreviations usually mark device classes, for whom and what they are intended for:
ASR - Aggregation Service Router, positioned as a router for providers.
ISR - Integrated Services Router, is positioned as a router for medium-sized and branches of large companies.
Catalyst is the traditional name for Cisco switches, it's like Intel's Pentium.
Nexus - switches for data centers.
XR is a more powerful operating system (IOS) in ISP Cisco routers.
The Cisco cloud router is a software ("non-hardware") router for the cloud, used in virtual networks of large cloud providers.
There is also a cloud switch, Nexus 1000v, which is installed in the VMware virtual infrastructure, so the logic of working with it differs from the hardware one.

Answer 3

Look here, I already wrote
And also flash courses on CCNA, on torrents, as mentioned above.

Answer 4

Try to read any book on cisco from beginning to end and everything will be clear to you
After reading the first page, cisco does not understand

Answer 5

Tsyski has good obtscheniyu courses. Everything is posted in torrents. Start with CCNA, then CCNP/CCIP. Well, communicate with more advanced engineers. You won't be fed up with books alone.

Answer 6

despite the fact that the answers above have already been given,
just read and master the ICND1 book at least = to the end and use Packet Tracer in parallel, this will give an idea.

Answer 7

Get started with courses from CBT Nuggets 640-802 by Jeremy Cioara.