Category: CCNA

Cisco Certified Network Associate certification resources
CCNA October 26, 2019

What is RSTP and Rapid PVST+: Exclusive Details

RSTP- IEEE 802.1w is the advanced version of STP, providing faster convergence than CST but holding with the same single root bridge in the topology. Most parameters in RSTP are the same as STP, so users who understand STP can effortlessly configure the RSTP. Rapid PVST+ is the Cisco proprietary of RSTP on a per-VLAN...
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CCNA October 25, 2019

What is PVST+ – Exclusive Explanation

The original IEEE 802.1D standard spanning tree protocol assumes only one spanning-tree instance for the entire switched network, regardless of the number of VLANs. A network running cannot ensure load balancing because one uplink must block for all VLANs but the CPU is free because there is only one instance of spanning tree working. The...
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CCNA October 24, 2019

Explain Types of Spanning-Tree Protocols

Spanning-Tree Protocol (STP) ensures network availability with redundant paths without a loop. Several types of spanning-tree protocols have appeared since the original IEEE 802.1D. The default spanning-tree mode for Cisco Catalyst switches is PVST+, which is enabled on all switch ports. The different types of spanning-tree protocols are:- Spanning-Tree Protocol (STP) The STP is the...
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Network switches exchanging BPDUs
CCNA October 22, 2019

802.1D Bridge Protocol Data Unit (BPDU) Frame Format

The spanning tree algorithm exchanges the Bridge Protocol Data Unit (BPDU) to elect the Root Bridge. It is a frame containing 12 different fields with different information. The information in the BPDU is used to determine the root bridge and the paths to the root bridge. The figure below illustrates the Bridge Protocol Data Unit...
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Network switches calculating path costs
CCNA October 19, 2019

Spanning Tree Algorithm – Path Cost Exclusive Details

When a loop occurs in the switched network, the STP uses path cost to resolve the port’s state. Path cost is obtained from the port’s speed. The spanning tree puts the lowest-numbered port into the forwarding state if all connected ports have the same path cost values. The path information is determined using the sum...
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Network diagram with switches, root bridge priority settings, and STP port roles (root, designated, blocked) labeled for clarity.
CCNA October 18, 2019

Spanning Tree – Root Bridge

Every spanning tree switched network or broadcast domain has a switch designated as the root bridge. It serves as the reference point for all spanning-tree-enabled switches. The spanning tree algorithm determines which redundant paths to block. It is selected as an election process. The figure below illustrates the bridge ID (BID) fields. BID is a...
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CCNA October 17, 2019

Spanning Tree – Port Roles

IEEE 802.1D Spanning Tree Protocol (STP) and Rapid Spanning Tree Protocol (RSTP) use the Spanning Tree Algorithm (STA) to decide which switch ports on a network must be put in a blocking state to prevent loops. The Spanning Tree Algorithm designates one switch in the network as the root bridge. The root bridge is considered...
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CCNA October 17, 2019

What is Spanning Tree Protocol

In the previous article, I have explained the redundancy. It increases the network availability by protecting the network from a single point of failure, such as a fault in a network cable or fault in a switch. When engineers introduce physical redundancy in design, loops and duplicate frames happen. I have written in the previous...
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CCNA October 16, 2019

What is Network Redundancy? – Exclusive Explanation

Reliability is the quality of a computer network that consistently performs according to its specifications. It has long been considered one of three related attributes that must be considered when planning a network. Network Redundancy is one of the key factors to maintain network reliability. Multiple physical connections between network devices provide redundant network paths....
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CCNA October 15, 2019

What is NAT for IPv6 – Exclusive Details

NAT and private IPv4 addresses have slowed down the depletion of IPv4 addresses, but NAT has some disadvantages. The one major benefit provided by NAT is security. NAT hides the private IPv4 network from the public Internet, providing a perceived level of security by denying computers on the public Internet from accessing internal hosts. However,...
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