Networking
CCNA tutorials, Cisco guides, and enterprise networking insights for IT professionals.
How to Configure Dynamic NAT (Updated 2025)
Dynamic Network Address Translation (NAT) is a cornerstone of modern networking, allowing multiple private IP devices to share a limited pool of public IPs for internet access. Unlike static NAT, dynamic NAT automatically maps inside local addresses to a pool of inside global addresses on a first-come, first-served basis—ideal for scenarios with more internal hosts...
How to Configure Static NAT on Cisco Routers
Static NAT maps inside and outside addresses one-to-one. It allows external devices to establish a session with internal devices using a statically assigned public address. For example, an internal web server is mapped to a specific inside global address, letting outside clients reach it using a public IP while the server itself keeps its private...
NAT Advantages and Disadvantages (Updated 2025
Network Address Translation (NAT) is a crucial topic in Cisco’s CCNA and CCNP curricula. It helps conserve IPv4 addresses and enhances security in enterprise networks. In this article, we’ll explore the pros and cons of NAT, with practical examples and tips for your certification exams. Network Address Translation (NAT) is a method used in IP...
What are the types of NAT translation? Exclusive Guide (Updated 2025)
There are three main types of NAT translation: static NAT, dynamic NAT, and port address translation (PAT). This guide is tailored for CCNA (200-301) and CCNP (ENCOR & ENARSI) students, with full Cisco IOS configurations, packet walk-throughs, verification commands, and troubleshooting tips. Static NAT Static NAT translation is also known as one-to-one NAT. Static NAT...
NAT Terminology Explained: CCNA 200-301 Must-Know Address Types
As discussed before, NAT translates private IP addresses into public IP addresses. In the process of translation, there are different operations involved, and understanding each of them requires understanding NAT terminology. Before understanding NAT in detail, it is important to understand the four NAT address types — inside local, inside global, outside local, and outside...
Network Address Translation (NAT) & RFC 1918 Private IPv4 Addresses – Exclusive Introduction
All public IPv4 addresses must be registered with a Regional Internet Registry (RIR). The registered holder of a public Internet address can assign these addresses to a network device. There is a maximum of 4.3 billion IPv4 addresses available. Still, with the increase of personal computing and the beginning of the World Wide Web, it...
How to Configure Stateful DHCPv6 Server
We can configure the stateful DHCPv6 server, similar to a stateless server. The difference between stateless and stateful is that a stateful server also includes IPv6 addressing information similar to a DHCPv4 server and obtains the state of the DHCP. Similar to stateless DHCPv6, we need to enable unicast routing. The command ipv6 unicast-routing enables...
Master Stateless DHCPv6 Server Configuration – A Complete Cisco Guide
Before a stateless DHCPv6 server is configured on the Cisco router, it is important to enable IPv6 unicast routing. The unicast routing is not necessary for stateless DHCPv6 servers, but it is required for RA messages due to the use of ICMPv6. In global configuration mode, we can enable the IPv6 unicast routing using the...
DHCPv6 Operation: Avoid Costly IPv6 Configuration Mistakes
Both of the stateless and stateful DHCPv6 operations are started with an ICMPv6 RA message from the router. The RA message may have been periodic or solicited by the device using an RS message. The devices start client and server communication when stateless or stateful DHCPv6 is indicated in the RA message. The DHCPv6 operation...
SLAAC and DHCPv6
Recall that the router sends a Router Advertisement (RA) message, and the settings within that RA message decide whether a client can obtain its IPv6 address information automatically using SLAAC, DHCPv6, or a combination of both. This guide covers both methods, the three possible RA flag combinations, and how to configure and verify each on...