Cisco commands – Expert Network Consultant https://www.expertnetworkconsultant.com Networking | Cloud | DevOps | IaC Wed, 29 Mar 2023 20:29:06 +0000 en-GB hourly 1 https://wordpress.org/?v=6.3.5 Building a Resilient Enterprise Network: A Step-by-Step Guide to Implementing a Three-Tier Design with Cisco Commands https://www.expertnetworkconsultant.com/expert-approach-in-successfully-networking-devices/building-a-resilient-enterprise-network-a-step-by-step-guide-to-implementing-a-three-tier-design-with-cisco-commands/ Fri, 31 Mar 2023 23:08:22 +0000 http://www.expertnetworkconsultant.com/?p=6063 Continue readingBuilding a Resilient Enterprise Network: A Step-by-Step Guide to Implementing a Three-Tier Design with Cisco Commands]]> The Three-Tier design is a network architecture that is commonly used in enterprise environments. It consists of a Core layer, a Distribution layer, and an Access layer. The Core layer provides high-speed connectivity and acts as the backbone of the network, the Distribution layer provides access to the Core layer and aggregates traffic from the Access layer, and the Access layer provides access to end devices such as servers, workstations, and printers. This design is also known as the Collapsed Core design because the Core layer and the Distribution layer are combined into a single layer.

To configure a Three-Tier design using Cisco commands, follow the steps below:

Configure the Core layer:

Configure the Core layer switches with high-speed links to provide the backbone of the network.
Configure the switchports connected to the Distribution layer switches as trunk ports.
Configure VLANs on the Core layer switches.

Sample Cisco commands:

interface GigabitEthernet0/1
switchport mode trunk
switchport trunk allowed vlan 10,20,30

Configure the Distribution layer:

Configure the Distribution layer switches with uplinks to the Core layer switches and downlinks to the Access layer switches.
Configure the switchports connected to the Core layer switches as trunk ports and the switchports connected to the Access layer switches as access ports.
Configure VLANs on the Distribution layer switches.

Sample Cisco commands:

interface GigabitEthernet0/1
switchport mode trunk
switchport trunk allowed vlan 10,20,30

interface GigabitEthernet0/2
switchport mode access
switchport access vlan 10

Configure the Access layer:

Configure the Access layer switches with uplinks to the Distribution layer switches.
Configure the switchports connected to end devices as access ports.
Configure VLANs on the Access layer switches.

Sample Cisco commands:

interface GigabitEthernet0/1
switchport mode access
switchport access vlan 10

interface GigabitEthernet0/2
switchport mode access
switchport access vlan 20

Configure Spanning Tree Protocol (STP):

Configure STP to prevent loops in the network.
Configure the Core layer switches as the root bridges for each VLAN.
Sample Cisco commands:

spanning-tree mode rapid-pvst
spanning-tree vlan 10,20,30 root primary

Configure Link Aggregation Control Protocol (LACP):

Configure LACP to provide link redundancy and load balancing between switches.
Sample Cisco commands:

interface GigabitEthernet0/1
channel-group 1 mode active

Configure VLANs:

Configure VLANs on the Core, Distribution, and Access layer switches to segment the network.
Assign ports to VLANs based on the device type and location.
Sample Cisco commands:

vlan 10
name Sales
vlan 20
name Engineering
vlan 30
name Marketing

Verify the configuration:

Verify the configuration by checking the switchport settings, VLAN configuration, and STP status.
Sample Cisco commands:

show interfaces GigabitEthernet0/1 switchport
show vlan brief
show spanning-tree vlan 10,20,30

By following these steps, you can configure a Three-Tier design using Cisco commands.

Follow a previous article on building a two tier campus network.
Design and Build a Two-Tier Campus Network Architecture

Follow this Cisco Validated Design for Inspiration.

Cisco Meraki has some good validated design ideas here.

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Configuring a Spanning Tree Protocol using Cisco Commands: A Step-by-Step Guide https://www.expertnetworkconsultant.com/expert-approach-in-successfully-networking-devices/configuring-a-spanning-tree-protocol-using-cisco-commands-a-step-by-step-guide/ Sat, 25 Mar 2023 14:43:06 +0000 http://www.expertnetworkconsultant.com/?p=6004 Continue readingConfiguring a Spanning Tree Protocol using Cisco Commands: A Step-by-Step Guide]]> A spanning tree is a protocol used in computer networks to prevent loops in the network topology. It works by creating a tree-like structure of network links that spans all the switches in the network, hence the name “spanning tree”. This article will explain what a spanning tree is and how to configure it using Cisco commands.

What is a Spanning Tree Protocol?

A Spanning Tree Protocol (STP) is a network protocol that prevents loops in a network topology by creating a logical tree-like structure of network links. This protocol is crucial because loops can cause broadcast storms, which can result in network congestion and ultimately, network failure.

There are several variations of the STP protocol, including the original STP, Rapid Spanning Tree Protocol (RSTP), and Multiple Spanning Tree Protocol (MSTP). These protocols differ in terms of their speed, complexity, and features.

Configuring a Spanning Tree with Cisco Commands

In this section, we will explain how to configure the STP protocol using Cisco commands. Specifically, we will use the example of configuring the RSTP protocol on a Cisco switch.

Enable RSTP on the switch
To enable RSTP on a Cisco switch, use the following command:

Switch(config)# spanning-tree mode rapid-pvst

This command enables the RSTP protocol on the switch and configures it to use the rapid-per-VLAN spanning tree (PVST) mode.

Configure the switch priority
Each switch in the network has a priority value, which determines the root bridge of the spanning tree. By default, the priority value is 32768. However, you can change this value using the following command:

Switch(config)# spanning-tree vlan  priority 

This command sets the priority value for a specific VLAN. For example, if you want to set the priority value for VLAN 10 to 16384, you would use the following command:

Switch(config)# spanning-tree vlan 10 priority 16384

Configure the root bridge
The root bridge is the switch that serves as the central point of the spanning tree. To configure a switch as the root bridge, use the following command:

Switch(config)# spanning-tree vlan  root primary

This command sets the switch as the root bridge for a specific VLAN. For example, if you want to set Switch 1 as the root bridge for VLAN 10, you would use the following command:

Switch(config)# spanning-tree vlan 10 root primary

Verify the spanning tree configuration
To verify the spanning tree configuration, use the following command:

Switch# show spanning-tree

This command displays information about the spanning tree, including the root bridge, port roles, and port states.

Conclusion

The Spanning Tree Protocol is an essential protocol for preventing network loops and ensuring network stability. In this article, we explained what the STP protocol is and how to configure it using Cisco commands. By following the steps outlined above, you can configure the RSTP protocol on a Cisco switch and ensure that your network is protected from loops and broadcast storms.

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