Networking Concepts and Configuration Guides

Check internet connectivity on Linux with curl to google.com, ping, DNS tools, and a shell script pattern — then work down routing and firewall layers when the quick check fails.

Fix Linux errno 99 (EADDRNOTAVAIL): when bind() fails because the IP is not local, when Docker publishes to a missing host address, when services start before the interface is ready, and when connect() exhausts ephemeral …

Configure BIND primary and secondary DNS on RHEL-family Linux with allow-transfer, slave zones, named-chroot on Rocky Linux 8, and dig verification after AXFR zone replication.

Learn how to use wireshark with different examples.

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Install and configure BIND on RHEL, Rocky Linux, or AlmaLinux with forward and reverse zones, controlled recursion, NetworkManager clients, and dig testing.

Migrate legacy network-scripts and ifcfg profiles to NetworkManager keyfiles on RHEL, Rocky Linux, AlmaLinux, Oracle Linux, and CentOS Stream before upgrading to a release that no longer reads ifcfg files.

Enable DNS over TLS on RHEL 10.1 or later with NetworkManager, dnsconfd, and unbound, then verify upstream DNS uses encrypted TCP port 853.

There are two methods to secure LDAP traffic. The first method is to using Secure Sockets Layer (SSL) /Transport Layer Security (TLS) technology. When this

Free, hands-on Wireshark tutorial covering capture, filters, decryption, TCP/UDP analysis, TLS/IPsec inspection, and real-world troubleshooting. 35+ packet-level examples with sample .pcap files included.

In this tutorial I am going to share step by step instructions to decrypt both HTTPS and LDAPS Traffic using WireShark. This tutorial is demonstrated using

Top 15 Wireshark IP filters cheat sheet with examples

Network loops occur due to many reasons. The most common causes are below.

Step-1: WinPcap comes with the older Wireshark versions in default. If you do not have it, download it from here (Winpcap website) and

6 different methods to configure and set static IP Address in Rocky Linux. Use nmtui, nmcli, ifcfg, ip and ifconfig utility to configure static IP address

Not defined, File not found, Access violation, Disk full or allocation exceeded, Unknown transfer ID, Unknown transfer ID, File already exists, No such user, Terminate transfer due to option negotiation

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Step by step instructions to detect rogue dhcp server in the network using wireshark. Introducing a rogue DHCP server to the network can block the clients from reaching network resources.

Virtual Router Redundancy Protocol (VRRP) is an open standard protocol, which has been developed by IEEE (Institute of Electrical and Electronics Engineers).

RDP can be vulnerable especially when Native RDP is used, which is protected by Standard RDP Security layer. CredSSP with NLA is the best option to go with.

In this tutorial we will explore step by step instructions to configure freeradius with LDAP and test authentication, authorization using wireshark

Step by step instructions to install and configure freeradius PAP and CHAP authentication with examples.

Protected EAP (PEAP) needs a certificate and TLS support. Thus, I will install "Active Directory Certificate Services" role.

After installing NPS and configuring the NAS (router) in Part 1, we will set up NPS for authentication, authorization, and accounting services.

Network Policy Server (NPS) is the Microsoft implementation of a Remote Authentication Dial-in User Service (RADIUS) server and proxy. A RADIUS server provides authentication, authorization, and accounting (AAA) …

Reliability is one of TCPs strong feature. TCP ensures that all packets one end sends will be delivered to the other end, keeping track of which packets have

In this article, we will cover Mutual Transport Layer Security (mTLS). The protocol provides a method for mutual authentication. Unlike general usage of TLS

In this article, we will focus on decrypting IPsec traffic between a Cisco router and a Strongswan IPsec VPN solution. Most of network vendors do not provide

Kerberos authentication presents several advantages over other network authentication methods.

Step-2: We need to check if the editing feature is enabled. Select the first packet from the list, then expand the Internet Protocol (IP) header tree. Next,