Email filtering with Sieve, Rspamd, and spam control
Level 2

Email filtering with Sieve, Rspamd, and spam control

Set up Sieve-based mail filtering, integrate Rspamd with Postfix for spam control, configure DKIM signing, Bayesian...

12 min
Dovecot IMAP and POP3: mailbox delivery and client access
Level 2

Dovecot IMAP and POP3: mailbox delivery and client access

Configure Dovecot for IMAP and POP3 access with TLS, authentication backends, LMTP delivery, quotas, shared mailboxes,...

10 min
Postfix mail server: installation, configuration, and relay control
Level 2

Postfix mail server: installation, configuration, and relay control

Install and configure Postfix with TLS, SASL authentication, relay restrictions, virtual domains, and production-grade...

10 min
Linux email architecture: MTA, MDA, MUA, and protocols explained
Level 2

Linux email architecture: MTA, MDA, MUA, and protocols explained

Understand the full email delivery chain on Linux: MTA, MDA, and MUA roles, SMTP/IMAP/POP3 with encryption, DNS records...

11 min
Linux routing, NAT, and packet forwarding
Level 2

Linux routing, NAT, and packet forwarding

Set up policy routing, SNAT/DNAT/MASQUERADE with nftables, GRE tunnels, and multi-table routing on Linux, with...

11 min
Network troubleshooting with tcpdump, ss, nmap, and traceroute
Level 2

Network troubleshooting with tcpdump, ss, nmap, and traceroute

Master network diagnostics using tcpdump packet capture, ss socket inspection, nmap scanning, traceroute path analysis,...

12 min
Advanced network configuration: bonding, bridging, and VLANs
Level 2

Advanced network configuration: bonding, bridging, and VLANs

Configure NIC bonding modes, Linux bridges for VMs and containers, 802.1Q VLANs, and team devices using nmcli and...

9 min
TCP/IP stack deep dive: protocols and Linux network internals
Level 2

TCP/IP stack deep dive: protocols and Linux network internals

Explore the Linux TCP/IP stack from socket buffers to netfilter hooks, covering protocol internals, /proc/sys/net...

12 min
Device mapper and storage virtualization on Linux
Level 2

Device mapper and storage virtualization on Linux

Understand the device mapper framework underpinning LVM, dm-crypt, and dm-cache. Explore dmsetup, Stratis as a modern...

11 min
Advanced LVM: thin provisioning, snapshots, and migration
Level 2

Advanced LVM: thin provisioning, snapshots, and migration

Go beyond basic LVM with thin pools, over-provisioning, snapshot workflows, pvmove for live migration, dm-cache for SSD...

11 min
iSCSI storage on Linux: targets, initiators, and multipath
Level 2

iSCSI storage on Linux: targets, initiators, and multipath

Configure iSCSI block storage on Linux using targetcli and open-iscsi, set up CHAP authentication, persistent mounts,...

10 min
Linux software RAID with mdadm: setup, management, and recovery
Level 2

Linux software RAID with mdadm: setup, management, and recovery

Build and manage Linux software RAID arrays with mdadm covering RAID 0/1/5/6/10, disk replacement, array growth, bitmap...

10 min