Author: Asad Ijaz

NetworkUstad's lead networking architect with CCIE certification. Specializes in CCNA exam preparation and enterprise network design. Authored 2,800+ technical guides on Cisco systems, BGP routing, and network security protocols since 2018. Picture this: I'm not just someone who writes about tech; I'm a certified expert in the field. I proudly hold the titles of Cisco Certified Network Professional (CCNP) and Cisco Certified Network Associate (CCNA). So, when I talk about networking, I'm not just whistling in the dark; I know my stuff! My website is like a treasure trove of knowledge. You'll find a plethora of articles and tutorials covering a wide range of topics related to networking and cybersecurity. It's not just a website; it's a learning hub for anyone who's eager to dive into the world of bits, bytes, and secure connections. And here's a fun fact: I'm not a lone wolf in this journey. I'm a proud member and Editor of Team NetworkUstad. Together, we're on a mission to empower people with the knowledge they need to navigate the digital landscape safely and effectively. So, if you're ready to embark on a tech-savvy adventure, stick around with me, Asad Ijaz Khattak. We're going to unravel the mysteries of technology, one article at a time!"
NAT terminology diagram showing inside local 192.168.1.100 translated to inside global 172.35.10.2 with outside local 20.41.5.19 and outside global 209.165.201.1
CCNA October 9, 2019

NAT Terminology Explained: CCNA 200-301 Must-Know Address Types

As discussed before, NAT translates private IP addresses into public IP addresses. So in the process of translation, there are different operations involved, and understanding each of them requires understanding NAT terminology. Therefore, before understanding NAT in detail, it is important to understand basic NAT terminology. In NAT terminology, the inside network is the set […]
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Stateful DHCPv6 topology showing server on G0/1 assigning 2001:ABCD:1:B::/64 prefix to client
CCNA October 6, 2019

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 […]
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DHCPv6 operation 6-step flowchart: Router Solicitation → Advertisement → SOLICIT to servers → Unicast Advertisement → REQUEST/INFO-REQUEST → Reply
CCNA October 5, 2019

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 […]
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Diagram illustrating three IPv6 address assignment methods via Router Advertisement (RA) flags: SLAAC (M=0, O=0), Stateless DHCPv6 (M=0, O=1), and Stateful DHCPv6 (M=1, O=1). Each section shows how a client interacts with a router and optionally a DHCPv6 server to obtain IPv6 configuration.
CCNA October 4, 2019

SLAAC and DHCPv6 – Exclusive Details

Remember that we already discussed the introduction of the SLAAC and DHCPv6 in Router Advertisement (RA) messages. Now, we will briefly discuss both SLAAC and DHCPv6. Recall that the router sends a Router Advertisement (RA) message. The setting of the Router Advertisement (RA) message decides whether a client can obtain its IPv6 address information automatically […]
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Network topology diagram in Cisco Packet Tracer showing routers, switches, servers, and laptops. Laptop0 displays a DHCP failure message with APIPA fallback.
CCNA September 30, 2019

What is DHCPv4 Relay?

In enterprise networks, dedicated servers are usually used to provide DHCP, DNS, TFTP, and FTP services. The clients are not generally on the same subnet as those servers. The clients used to broadcast messages to locate the servers and get services. Now, look at the figure below. Laptop0 is attempting to acquire an IPv4 address […]
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Diagram illustrating DHCPv4 server configuration and verification with a Cisco router and DHCP client.
CCNA September 29, 2019

Master DHCPv4 Server Configuration (Updated 2025)

A Cisco router can be configured as a DHCPv4 server. The DHCPv4 server assigns and manages IPv4 addresses from specified address pools within the router to DHCPv4 clients. The steps for configuring the DHCPv4 server on Cisco routers are the following: Excluding IPv4 Addresses The router configured as the DHCPv4 server assigns all IPv4 addresses […]
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