Configuration for GLBP

Before diving into the load balancing methods within GLBP, let’s start with the basic configuration of GLBP.

RouterA(config)# interface GigabitEthernet0/0
RouterA(config-if)# ip address
RouterA(config-if)# glbp 1 ip
RouterA(config-if)# glbp 1 priority 100
RouterA(config-if)# glbp 1 preempt

In this initial configuration, we’ve set up RouterA for GLBP with group 1, assigned it an IP address, set the virtual IP address, and configured a priority of 100, making it the initial Active Virtual Gateway (AVG). The “preempt” command ensures RouterA becomes AVG again when it recovers.

Load Balancing in GLBP

GLBP offers three load balancing methods: round robin, weighted, and host-dependent. Each method serves different network requirements. Let’s explore these methods and their configurations.

Round Robin Load Balancing

This is the default load balancing method in GLBP. In round robin, each virtual forwarder MAC address responds sequentially for the virtual IP address. It evenly distributes traffic among all active virtual forwarders. This is suitable for scenarios where all routers have similar capacities and should share traffic equally.

RouterA(config-if)# glbp 1 load-balancing round-robin

Weighted Load Balancing

In weighted load balancing, you assign weights to each device within the GLBP group. These weights define the ratio of load balancing between devices. This method allows you to allocate a larger weight to more powerful routers capable of handling heavier traffic loads. Weighted load balancing is particularly useful in heterogeneous network environments with routers of varying capacities.

RouterA(config-if)# glbp 1 load-balancing weighted
RouterA(config-if)# glbp 1 weighting 150
RouterB(config-if)# glbp 1 weighting 100

Host-Dependent Load Balancing

Host-dependent load balancing uses the host MAC address to determine which virtual forwarder MAC should handle the incoming packet. This method ensures that the host consistently uses the same virtual MAC address, as long as the number of virtual forwarders in the group remains constant. Host-dependent load balancing is suitable for applications where session persistence or stickiness is required, such as in some web applications.

RouterA(config-if)# glbp 1 load-balancing host-dependent


GLBP’s load balancing methods, including round robin, weighted, and host-dependent, offer a range of options to suit different network requirements. Understanding and configuring these methods is crucial for network professionals pursuing the CCNP ENCOR certification, as it enables efficient, resilient, and high-performing networks tailored to specific needs.


CCNP Master Class

CCNP Master Class

VTP Configuration Commands:

Task Command Syntax
Configure the VTP version vtp version {1 | 2 | 3}
Configure the VTP domain name vtp domain domain-name
Configure the VTP mode for a switch vtp mode { server | client | transparent | none}
Configure a switch to become the primary VTP server vtp primary

Switchport and EtherChannel Configuration Commands:

Task Command Syntax
Configure a switch port to actively establish a trunk link switchport mode dynamic desirable
Configure a switch port to respond to remote attempts to establish a trunk link switchport mode dynamic auto
Configure the member ports for a static EtherChannel channel-group etherchannel-id mode on
Configure the member ports for an LACP EtherChannel channel-group etherchannel-id mode {active | passive}
Configure the member ports for a PAgP EtherChannel channel-group etherchannel-id mode {auto | desirable} [non-silent]
Configure the LACP packet rate lacp rate {fast | slow}
Configure the minimum number of member links for the LACP EtherChannel to become active port-channel min-links min-links
Configure the maximum number of member links in an LACP EtherChannel lacp max-bundle max-links
Configure a switch’s LACP system priority lacp system-priority priority
Configure a switch’s LACP port priority lacp port-priority priority
Configure the EtherChannel load-balancing hash algorithm port-channel load-balance hash

Display Commands:

Task Command Syntax
Display the contents of all current access lists show access-list [access-list-number | access-list-name]
Display the VTP system settings show vtp status
Display the switch port DTP settings, native VLANs, and allowed VLANs show interface [interface-id] trunk
Display a brief summary update on EtherChannel interfaces show etherchannel summary
Display detailed information for the local EtherChannel interfaces and their remote peers show interface port-channel
Display information about LACP neighbors show lacp neighbor [detail]
Display the local LACP system identifier and priority show lacp system-id
Display the LACP counters for configured interfaces show lacp counters
Display information about PAgP neighbors show pagp neighbor
Display the PAgP counters for configured interfaces show pagp counters
Display the algorithm for load balancing network traffic based on the traffic type show etherchannel load-balance


ccna trainer in usa

ccna trainer in usa

In the ever-evolving landscape of cybersecurity, the need for skilled professionals who can safeguard networks and data has never been greater. The journey to becoming a cybersecurity expert often begins with certifications, and while there are various paths to choose from, one common thread among them is the fundamental knowledge of networking and routing. In this article, we will explore why a strong grasp of networking concepts is essential before pursuing any cybersecurity certification and why the Cisco Certified Network Associate (CCNA) stands out as a vital step in this journey.

The Foundation of Cybersecurity

Cybersecurity, at its core, is about protecting digital assets and systems from unauthorized access, attacks, and data breaches. These assets typically reside on computer networks, making networking knowledge a foundational requirement for cybersecurity professionals. Understanding how data flows, how devices communicate, and how networks are structured is paramount to identifying and mitigating security threats effectively.

Why Networking Knowledge Matters

  • Understanding Attack Surfaces: Network devices and protocols are potential entry points for cyber threats. Professionals with networking knowledge can identify vulnerabilities and implement appropriate safeguards, reducing the attack surface.
  • Traffic Analysis: Anomalies in network traffic can be early indicators of a security breach. Networking experts are adept at analyzing network traffic patterns to detect and respond to suspicious activities promptly.
  • Effective Defense Strategies: Cybersecurity measures often involve configuring firewalls, intrusion detection systems, and access control lists. A strong networking foundation is crucial for correctly configuring these devices to protect the network.
  • Incident Response: In the event of a security incident, understanding network logs and traffic is vital for incident responders. Knowledge of networking protocols helps pinpoint the source and impact of an attack.
  • Securing Cloud Environments: Many organizations are transitioning to cloud-based solutions. A grasp of networking fundamentals ensures secure cloud integration and data protection.

The CCNA Advantage

While there are several networking certifications available, Cisco’s CCNA stands out as an ideal choice for those embarking on a cybersecurity journey. Here’s why:

  • Comprehensive Networking Knowledge: CCNA covers a broad spectrum of networking topics, including routing, switching, security, and more. This knowledge is invaluable in building a strong foundation for cybersecurity.
  • Industry Recognition: Cisco is a global leader in networking technologies, and CCNA is a well-respected certification recognized by employers worldwide. Holding a CCNA demonstrates your commitment to networking excellence.
  • Hands-On Experience: CCNA emphasizes hands-on labs and practical exercises. This hands-on experience is invaluable for understanding how networking concepts apply in real-world scenarios, making it easier to tackle cybersecurity challenges.
  • Prerequisite for Higher Certifications: Many advanced cybersecurity certifications, such as Certified Information Systems Security Professional (CISSP) or Certified Information Security Manager (CISM), require a solid networking foundation. CCNA fulfills this prerequisite.
  • Career Advancement: CCNA is an excellent entry point into the IT industry. It opens doors to various IT roles, including network administration, which can serve as stepping stones to cybersecurity positions.


In the world of cybersecurity, where threats are constantly evolving, a strong understanding of networking is indispensable. Networking knowledge provides the groundwork upon which robust cybersecurity strategies are built. Cisco’s CCNA certification offers an ideal path to acquiring this essential knowledge. By starting with CCNA, aspiring cybersecurity professionals can build a solid foundation that will not only pave the way for successful certification but also enhance their ability to protect networks and data from cyber threats, ensuring a safer digital world for all.

Online CCNA in Boston

Online CCNA in Boston


Freelancer IT Trainer Mr. Saeed Ahmad: Empowering Minds in Networking Through Expert Instruction

In the rapidly evolving world of technology, the demand for skilled IT professionals is soaring. To meet this growing need for expertise in networking, online courses have become a popular and accessible way for aspiring professionals to acquire essential skills. Among the many dedicated trainers in this field, one name stands out: Mr. Saeed Ahmad, a Cisco Netacad Certified and Expert Level Instructor who provides top-notch online networking courses as a freelancer.

Recognition and Awards

Mr. Saeed Ahmad’s journey as an IT instructor has been nothing short of exemplary. His dedication and commitment to his students have been acknowledged on multiple occasions through prestigious awards and recognition. Among the notable awards he has received are the “Instructor Excellence Expert” awards in 2015, 2016, and 2017, a testament to his consistent and outstanding performance as an instructor.

Additionally, in 2013 and 2017, Mr. Ahmad was honored for his long-standing service in the industry, celebrating his 5 and 10 years of service milestones, respectively. Such recognition speaks volumes about his unwavering passion for teaching and mentoring IT enthusiasts.

A Vast Array of Courses

One of the distinguishing features of Mr. Saeed Ahmad’s teaching repertoire is the broad range of courses he is eligible to instruct. The diverse selection includes courses ranging from basic networking essentials to advanced cybersecurity and programming. As a Cisco Netacad Certified instructor, his expertise extends to courses such as CCNA Cybersecurity Operations, CCNA Security, and CCNA R&S (Routing and Switching) series, which comprises several modules like “Connecting Networks,” “Introduction to Networks,” “Routing and Switching Essentials,” and “Scaling Networks.”

Apart from Cisco-specific courses, Mr. Ahmad’s proficiency spans across various other areas, including emerging technologies, entrepreneurship, IoT (Internet of Things) fundamentals, network security, and cloud security. His ability to teach a wide range of subjects makes him an invaluable resource for anyone looking to delve into the exciting world of IT.

A Passion for Empowering Learners

Mr. Saeed Ahmad’s success as a freelancer IT trainer can be attributed to his passion for empowering learners. His approach to instruction involves creating a nurturing and interactive learning environment where students feel encouraged to ask questions and explore concepts. His dedication to making complex topics more accessible, coupled with real-world examples, ensures that students not only grasp theoretical knowledge but also gain practical insights.

As an Expert Level Instructor, Mr. Ahmad’s teaching methods are informed by years of experience and in-depth expertise in the networking domain. This wealth of knowledge allows him to effectively guide students through the intricacies of IT, ensuring they gain not just the skills needed for exams but also the confidence to apply their knowledge in real-world scenarios.

Embracing the Advantages of Freelancing

Embracing the flexibility and freedom that comes with freelancing, Mr. Saeed Ahmad has been able to reach a diverse audience of learners worldwide. Online platforms have allowed him to transcend geographical barriers, making quality IT education accessible to individuals from all walks of life. This global reach not only benefits students but also enriches the learning experience as diverse perspectives are shared and discussed.


In a rapidly advancing digital landscape, the role of IT trainers like Mr. Saeed Ahmad is paramount. His expertise as a Cisco Netacad Certified and Expert Level Instructor, combined with a multitude of awards recognizing his excellence, showcases his unwavering commitment to providing top-notch online networking courses. Through his passionate and empowering teaching approach, learners are equipped with the skills and knowledge needed to excel in the competitive world of IT. As the demand for skilled IT professionals continues to grow, Mr. Ahmad’s contributions as a freelancer IT trainer remain instrumental in shaping the future of the industry, one student at a time.

Freelancer IT Trainer

Freelancer IT Trainer

CCNA stands for Cisco Certified Network Associate. It is an entry-level certification offered by Cisco Systems, a leading provider of networking and telecommunications equipment. CCNA validates the knowledge and skills required to install, configure, operate, and troubleshoot small to medium-sized networks.

CCNA is important for several reasons:

1. Industry Recognition: CCNA is recognized worldwide as a valuable certification in the IT industry, particularly in the field of networking. It demonstrates a strong foundation in network fundamentals and Cisco technologies.

2. Career Advancement: CCNA certification can open doors to various career opportunities, including network engineering, network administration, and technical support roles. It provides a solid foundation for further Cisco certifications and career growth in the networking field.

3. Enhanced Skills and Knowledge: Pursuing CCNA helps individuals develop a comprehensive understanding of networking concepts, protocols, and best practices. It equips professionals with the skills needed to configure and troubleshoot networks effectively.

As for job opportunities and salary ranges, here are some statistics:

– As of July 2023, there are 6,047 CCNA job listings in the United States. The estimated total pay for a Network Engineer (CCNA) is $91,024 per year, with an average salary of $81,606 per year.

– The average CCNA salary in the USA is $82,500 per year or $39.66 per hour, based on 659 salaries.

– The average annual salary for a CCNA in the USA is $77,309, slightly higher than the national average of $73,924.

– Entry-level Network Engineers with CCNA certification can expect an estimated salary range of $69,000 to $87,400 per year.

– There are over 185,000 CCNA job listings in the United States, with thousands of new listings added regularly.

These statistics demonstrate the demand for professionals with CCNA certification and the competitive salary ranges associated with CCNA-related roles.

In summary, CCNA certification provides industry recognition, enhances skills and knowledge, and offers numerous job opportunities in the field of networking. It serves as a stepping stone for career advancement and provides a solid foundation for further Cisco certifications.

  1. show running-config: This command displays the current configuration of the device, including all the configured settings.
  2. show ip protocols: This command displays information about the IP routing protocols enabled on the device, including OSPF.
  3. show ip ospf interface: This command shows detailed information about OSPF interfaces, including their state, cost, and other parameters.
  4. show ip ospf interface type number: This command is used to display specific information about a particular OSPF interface based on its type and number.
  5. show ip ospf interface brief: This command provides a summary of OSPF interfaces, including their interface ID, state, and IP addresses.
  6. show ip ospf neighbor: This command displays information about OSPF neighbors, including their IP addresses, priority, and state.
  7. show ip ospf neighbor type number: This command shows specific information about a particular OSPF neighbor based on its type and number.
  8. show ip ospf database: This command provides information about the OSPF link-state database, including the contents of the LSAs (Link-State Advertisements).
  9. show ip ospf rib: This command displays the OSPF routing information base, which contains the routes learned through OSPF.
  10. show ip route: This command shows the IP routing table, including all the routes learned by the device.
  11. show ip route ospf: This command displays the subset of IP routes in the routing table that were learned through OSPF.
  12. show ip route subnet mask: This command filters the IP routing table to display routes matching a specific subnet mask.
  13. show ip route | section subnet: This command filters the IP routing table to display the section of routes that contain a specific subnet.

Remember, these commands may vary depending on the device’s operating system and software version. It’s always best to refer to the device’s documentation or consult with a network administrator for specific command usage and interpretation.

ospf verification commands

ospf verification commands


Baseline Equipment Bundle:

  • 2 x ISR4221/K9 Routers
  • 2 x WS-C2960+24TC-L Catalyst switches
  • 1 wireless router (generic brand) with WPA2 support
  • Ethernet patch cables
  • PCs – minimum system requirements:
    • CPU: Intel Pentium 4, 2.53 GHz or equivalent
    • OS: Microsoft Windows 7, Microsoft Windows 8.1, Microsoft Windows 10, Ubuntu 14.04 LTS, macOS High Sierra and Mojave
    • RAM: 4 GB
    • Storage: 500 MB of free disk space
    • Display resolution: 1024 x 768
    • Language fonts supporting Unicode encoding (if viewing in languages other than English)
    • Latest video card drivers and operating system updates
  • Internet connection for lab and study PCs
  • Optional equipment for connecting to a WLAN:
    • 1 printer or integrated printer/scanner/copier for the class to share
    • Smartphones and tablets are desirable for use with the labs


  • Cisco IOS versions:
    • Routers: Version IOS XE 16.0 or higher, IP Base feature set
    • Switches: Version IOS 15.0 or higher, lanbaseK9 feature set
  • Cisco Packet Tracer Stable release: 8.2 download
  • Open-source server software:
    • For various services and protocols, such as Telnet, SSH, HTTP, DHCP, FTP, TFTP, etc.
  • Tera Term source SSH client software for lab PCs
  • Oracle VirtualBox, most recent version
  • Wireshark version 2.5 or higher
InterVLAN Routing Using Layer III Switch with SVI

InterVLAN Routing Using Layer III Switch with SVI


To understand how to work with inter-VLAN routing using Layer 3 switch SVI (Switched Virtual Interface) interface.

Steps to Configure Inter-VLAN Routing:

1. Configure VLANs:

Start by creating the VLANs you want to use for inter-VLAN routing. Assign unique VLAN IDs and assign the required interfaces to their respective VLANs.

2. Enable IP routing:

Enable IP routing on the Layer 3 switch. This allows the switch to route traffic between VLANs.

3. Configure SVI interfaces:

Create SVI interfaces for each VLAN that requires inter-VLAN routing. An SVI acts as a virtual interface representing a VLAN on the Layer 3 switch. Assign an IP address to each SVI interface within the corresponding VLAN subnet.

4. Enable SVI interfaces:

Enable each SVI interface to bring it up and allow it to participate in inter-VLAN routing.

5. Configure default gateway:

Specify the default gateway IP address on the Layer 3 switch. This is typically the IP address of the router that connects the switch to other networks.

6. Add static routes:

If there are additional networks beyond the connected VLANs, add static routes on the Layer 3 switch to ensure proper routing between those networks and the VLANs.


Let’s assume we have a Layer 3 switch with two VLANs, VLAN 10 and VLAN 20. We want to enable inter-VLAN routing between these VLANs using SVI interfaces.

1. Configure VLANs:

VLAN 10: Assign interfaces Fa0/1, Fa0/2 to VLAN 10.
VLAN 20: Assign interfaces Fa0/3, Fa0/4 to VLAN 20.

2. Enable IP routing:

Enable IP routing on the Layer 3 switch.

3. Configure SVI interfaces:

VLAN 10 SVI: Configure interface VLAN 10 with IP address
VLAN 20 SVI: Configure interface VLAN 20 with IP address

4. Enable SVI interfaces:

Activate VLAN 10 SVI and VLAN 20 SVI.

5. Configure default gateway:

Set the default gateway IP address to the IP address of the connected router 

6. Add static routes:

If there are additional networks beyond VLANs 10 and 20, add static routes to those 
networks via the Layer 3 switch.

With this configuration, devices connected to VLAN 10 can communicate with devices in VLAN 20 by using the SVI interfaces as the gateway. For example, a device with IP address in VLAN 10 can communicate with a device with IP address in VLAN 20 by sending traffic to their respective SVI IP addresses.

By following these steps and configuring the necessary settings, you can achieve inter-VLAN routing using Layer 3 switch SVI interfaces.

Posted by Saeed Ahmad, CCNAGuru
InterVLAN Routing Using Layer III Switch with SVI

InterVLAN Routing Using Layer III Switch with SVI


Spanning Tree Path Cost

Spanning Tree Protocol (STP) is a network protocol that ensures loop-free topologies in Ethernet networks. One of the key elements in STP is the concept of path cost, which determines the best path for data forwarding in the network. Path cost is assigned to each network link based on its speed. The following table provides the default STP port costs for different link speeds:

Link Speed Short-Mode STP Cost Long-Mode STP Cost
10 Mbps 100 2,000,000
100 Mbps 19 200,000
1 Gbps 4 20,000
10 Gbps 2 2,000
20 Gbps 1 1,000
100 Gbps 1 200
1 Tbps 1 20
10 Tbps 1 2

Understanding Spanning Tree Path Cost

Spanning Tree Path Cost represents the cost associated with transmitting data over a particular network link. The STP cost ensures that the network path selection prefers higher-speed links over lower-speed links. The lower the cost, the more desirable the path becomes for forwarding traffic.

In Short-Mode, which is the default mode for STP, the path costs are calculated based on the values mentioned in the “Short-Mode STP Cost” column in the table. However, in some instances, the “Long-Mode STP Cost” is used for path cost calculation. This is typically encountered in Rapid Spanning Tree Protocol (RSTP) or Multiple Spanning Tree Protocol (MSTP) scenarios.

It is important to note that the default STP path costs can be modified in certain network equipment to suit specific requirements or to influence path selection.


Understanding Spanning Tree Path Cost is crucial in building efficient and loop-free Ethernet networks. By assigning appropriate costs to

network links based on their speeds, Spanning Tree Protocol ensures optimal path selection. The default path costs provided in the table serve as a reference, but it is important to verify and adjust these values as needed in your specific network environment.

To configure and monitor OSPF (Open Shortest Path First) on a Cisco router, you can use various commands. These commands allow you to enable OSPF, modify OSPF settings for interfaces, view OSPF information, and more. Below is a list of commonly used OSPF commands along with their details:

Command Details
router ospf 123 Turns on OSPF process number 123. The process ID is any value between 1 and 65,535. The process ID does not equal the OSPF area.
network area 0 OSPF advertises interfaces, not networks. Uses the wildcard mask to determine which interfaces to advertise. The command shown reads: Any interface with an address of 172.16.10.x is to be put into Area 0.
ip ospf priority 50 Changes the OSPF priority for an interface to 50.
bandwidth 128 Changes the bandwidth of an interface to 128 kbps.
ip ospf cost 1564 Changes the cost to a value of 1564.
ip ospf hello-interval 20 Changes the Hello interval timer to 20 seconds.
ip ospf dead-interval 80 Changes the Dead interval timer to 80 seconds.
ip route s0/0/0 Creates a static default route pointing out the Serial 0/0/0 interface. This route will have an administrative distance of 0.
default-information originate Sets the default route to be propagated to all OSPF routers.
show ip protocol Displays parameters for all routing protocols running on the router.
show ip route Displays the complete IP routing table.
show ip ospf Displays basic OSPF information for all OSPF processes running on the router.
show ip ospf interface Displays OSPF information as it relates to all interfaces.
show ip ospf neighbor List all the OSPF neighbors and their states.
show ip ospf neighbor detail Displays a detailed list of neighbors.

Command Reference OSPF