Basic concept

Areas to dive deep:

1. Networking Fundamentals:

   • Understand the OSI model and TCP/IP protocol suite.

   • Learn about IPv4 and IPv6 addressing, subnetting, and routing.

   • Familiarize yourself with common networking terms, concepts, and protocols like Ethernet, ARP, ICMP, DNS, DHCP, NAT, VLANs, etc.

2. Linux Networking Stack:

   • Study the Linux networking stack architecture, including the kernel networking subsystem.

   • Learn about network namespaces, which provide isolated network environments.

   • Understand how Linux handles network packets, routing, and packet filtering using netfilter/iptables and nftables.

   • Explore the role of device drivers, network interfaces, and kernel modules in Linux networking.

3. Network Configuration and Tools:

   • Gain proficiency in configuring network interfaces, routes, and DNS settings using tools like ifconfig, ip, route, and resolv.conf.

   • Learn about network bonding, VLAN configuration, and bridge interfaces.

   • Explore advanced networking configurations using tools like NetworkManager and systemd-networkd.

4. Network Services and Protocols:

   • Deep dive into common network services like DHCP, DNS, NTP, LDAP, SSH, FTP, HTTP, etc., and their configuration on Linux.

   • Understand how Linux implements network protocols such as TCP, UDP, ICMP, SNMP, TLS/SSL, etc.

   • Explore network security mechanisms and practices, including firewalls, VPNs, encryption, authentication, etc.

5. Monitoring and Troubleshooting:

   • Learn to use network monitoring and diagnostic tools like tcpdump, Wireshark, netstat, ss, iptraf, traceroute, ping, mtr, nslookup, etc.

   • Develop skills in troubleshooting common networking issues, including connectivity problems, performance issues, DNS resolution problems, etc.

   • Understand how to analyze network traffic and interpret packet captures for debugging purposes.

6. Performance Tuning and Optimization:

   • Explore techniques for optimizing network performance and throughput on Linux systems.

   • Learn about kernel tuning parameters, TCP congestion control algorithms, buffer sizes, and other performance-related settings.

   • Understand the impact of hardware offloading, interrupt handling, and kernel bypass mechanisms on network performance.

7. Network Security and Hardening:

   • Study network security best practices and techniques for securing Linux systems against common threats.

   • Learn about firewall configuration, access control lists (ACLs), intrusion detection and prevention systems (IDS/IPS), SELinux, AppArmor, etc.

   • Stay updated on security vulnerabilities and patches related to the Linux networking stack.

TLS termination

TLS termination refers to the process of decrypting encrypted traffic (typically using TLS or SSL protocols) at a network boundary, such as a load balancer, reverse proxy, or gateway, before forwarding it to its destination. In other words, TLS termination involves terminating the TLS connection and decrypting the data so that it can be processed or inspected by intermediary devices.

Here's how TLS termination works in a typical scenario:

1. Client initiates a TLS connection: A client (such as a web browser) initiates a TLS handshake with a server to establish a secure connection. This involves negotiating encryption parameters and exchanging cryptographic keys.

2. Traffic reaches the TLS termination point: The encrypted traffic reaches a network device acting as a TLS terminator, such as a load balancer or reverse proxy server, before reaching the destination server.

3. TLS termination: The TLS terminator terminates the TLS connection by decrypting the incoming traffic using the private key associated with the SSL/TLS certificate installed on the terminator. This allows the terminator to access the plaintext data.

4. Processing or inspection: After decryption, the plaintext data can be processed, inspected, or modified by the TLS terminator. This might include load balancing decisions, content inspection for security purposes, or other forms of traffic manipulation.

5. Forwarding to the destination: Once processed, the decrypted data is forwarded to the destination server or service within the internal network in plaintext.