Networking
CCNA tutorials, Cisco guides, and enterprise networking insights for IT professionals.
NTS- Pakistan Studies Test-1
The National Testing Service (NTS) is a cornerstone of standardized testing in Pakistan, yet its influence and operational nuances remain widely misunderstood. Despite its ubiquity in academic and professional assessments, misconceptions about its processes, validity, and impact persist. A 2026 study by the Pakistan Institute of Education found that 68% of test-takers believe NTS results...
How to EIGRP automatic summarization
Route summarization is the most common tuning method of EIGRP. It allows a router to group multiple networks and advertises them as one large group using a single, summarized route. The capability to summarize routes is very important due to the rapid growth of networks. Route summarization reduces the number of routes in a larger...
Topology Table – Exclusive Introduction
The EIGRP topology table contains all of the information about all known routes received from EIGRP neighbors. As an EIGRP router learns routes from its neighbors, those routes are stored in its EIGRP topology table. If a neighbor is advertising a possible route, it has to be using that route to forward packets to the...
Successor, Feasible Successor and Feasible Distance
Successor -A successor route is the best route to a destination network. EIGRP uses the successor route to forward traffic to a destination. This is the router which is stored in the routing table. A successor route is based on the advertised distance from the neighbor. A successor route is a least-cost route to the...
What is DUAL?
The diffusing update algorithm (DUAL) is the algorithm used by EIGRP routing protocol to make sure that a given route is recalculated globally whenever it might cause a routing loop. It is guarantees loop-free and backup paths throughout the routing domain. EIGRP store all available backup routes using diffusing update algorithm and then adapt the...
How to Calculate EIGRP Metric
EIGRP automatically calculates the routing table metric to choose the best path. But it is important that the network administrator understands how to calculate EIGRP metric. The default formula for the composite metric is: [k1 x Bandwidth + k3 x delay] x 256 By default K1 and K3 is equal to 1 so the formula...
Introduction to Delay Metric
A network engineer at a Tier 1 ISP spent three weeks troubleshooting intermittent VoIP call drops before discovering the root cause: an incorrectly weighted delay metric in their OSPF routing tables. The fix took nine minutes. How Delay Metrics Dictate Traffic Flow in Modern Networks Delay metrics measure the time it takes for a packet...
Introduction to Bandwidth Metric
A network engineer stares at a traceroute that defies logic — traffic flows across a 10 Mbps satellite link while a 1 Gbps fiber path sits idle. The root cause isn’t a hardware fault. It’s a misconfigured bandwidth metric. Across every major routing protocol and QoS framework, the bandwidth metric quietly dictates which path packets...
EIGRP Composite Metric – Exclusive Explanation
A composite metric is a number calculated based on several different components that determine the preferred route. By default, EIGRP uses bandwidth and delay to calculate the preferred path to a network. The reliability and load can also be used, but are not recommended, because they typically result in a frequent recalculation of the topology...
What is EIGRP Topology Table
EIGRP uses a neighbor table, topology table, and IP routing table. The neighbor table maintains a state of neighbors. The topology table is used to store information about all known routes received from all neighbors. EIGRP Update messages send the routers’ EIGRP topology tables. The EIGRP topology table is a database of possible routes. Each...