OPEN LEARNING LIBRARY

Knowledge Base

Practical lessons for Linux, Cisco and MikroTik. Search by topic or filter by category.

Linux / Beginner

Linux filesystem and core directories

Understand the purpose of /, /home, /etc, /var and /usr.

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Linux / Beginner

Linux permissions: chmod, chown and rwx

Read, write and execute permissions for files and directories.

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Linux / Intermediate

Manage services with systemd and systemctl

Inspect, start and enable Linux services.

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Linux / Advanced

LVM basics: PV, VG and LV

Understand Physical Volumes, Volume Groups and Logical Volumes.

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Cisco / Beginner

The OSI model: understanding its seven layers

Understand network communication through seven layers.

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Cisco / Intermediate

Cisco VLAN and trunk configuration

Create VLANs and configure access and trunk ports on a switch.

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Cisco / Intermediate

Inter-VLAN routing: router-on-a-stick

Configure communication between devices in different VLANs.

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Cisco / Advanced

OSPF: neighbor relationships and basic configuration

OSPF process, router ID and network statements.

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MikroTik / Beginner

MikroTik DHCP Server: initial configuration

Understand IP pools, DHCP networks and DHCP servers.

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MikroTik / Intermediate

MikroTik NAT and masquerade

Allow a LAN network to access the internet.

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Linux / Intermediate

Linux network diagnostics

Inspect networking with ip, ping, traceroute, ss and DNS tools.

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Cisco / Advanced

OSPF multi-area fundamentals

Understand Area 0, ABRs and hierarchical routing design.

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MikroTik / Beginner

Back up a MikroTik configuration

Understand the difference between binary backups and configuration exports.

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Linux / Beginner

Linux users and groups

Users and groups are central to access control in Linux. A process normally runs with a user ID (UID) and group IDs (GIDs).

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Linux / Intermediate

SSH: secure remote access

SSH provides an encrypted connection to a remote Linux host. The server needs OpenSSH Server installed and the sshd service runnin

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Linux / Intermediate

Inspect Linux disks and filesystems

Disk administration starts by identifying devices, partitions, mount points and available capacity. Always verify the target devic

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Cisco / Intermediate

Spanning Tree Protocol (STP) fundamentals

Redundant physical paths in Layer 2 switched networks can create loops. STP prevents Layer 2 loops by blocking some redundant path

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Cisco / Intermediate

Cisco ACL: standard and extended access lists

An Access Control List (ACL) permits or denies traffic based on IP addresses, protocols and ports. Cisco ACLs are processed top-do

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MikroTik / Intermediate

MikroTik Firewall Filter: input, forward, output

RouterOS firewall filter processes traffic through three main chains: input — traffic destined for the router, forward — traffic r

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MikroTik / Advanced

MikroTik Bridge VLAN Filtering fundamentals

MikroTik RouterOS bridge VLAN filtering provides Layer 2 VLAN segmentation similar to a switch. The configuration relies on PVID,

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The knowledge base is public. New lessons will be added based on hands-on learning, official documentation and practical testing.