Configurations

∙VLAN 1 is not used for management. All ports in Catalyst switches default to VLAN 1, and any devices connected to non−configured ports will be in VLAN 1. This may cause potential issues for the management of switches, as explained above.

∙A Layer 3 (L3) (routed) port is used to connect to the default gateway port. In this diagram, a Cisco 7200VXR router could be easily replaced by a firewall that connects to the Internet gateway router.

∙A routing protocol is not run between the stack of Catalyst 3750s and the Internet gateway router. Instead, a static default route is configured on the 3750. This setup is preferred if there is only one route to the Internet. Make sure to configure static routes (preferably summarized) on the gateway router (7200VXR) for subnets that can be reached by the Catalyst 3750s. This step is very important since routing protocols are not being used.

∙If you need additional bandwidth for the uplink ports, you can configure EtherChannel. Configuring EtherChannel also provides link redundancy in case of a link failure.

This document uses the configurations shown below.

∙Catalyst 3750

∙Catalyst 2950

∙Catalyst 2948G

As you can see below, although there are two Catalyst 3750 switches stacked together, they are configured just as if they had only one switch. Both switches have twenty−four 10/100/1000 interfaces and in the configuration they show up as gigabit Ethernet 1/0/1 up to gigabit 1/0/24 for the first switch, and gigabit 2/0/1 up to gigabit 2/0/24 for the second one. So looking at the configuration, it appears as if there is just one switch with two modules that each have 24 ports.

Extending this exercise to 3, 4, 5, and so on, switches in a stack would appear similar, but for each switch that is added to the stack, it shows up in the configuration as if one module is added to the switch.

Cat3750 (Cisco Catalyst 3750G−24T)

C3750G−24T#show run Building configuration...

Current configuration : 2744 bytes

version 12.1 no service pad

service timestamps debug uptime service timestamps log uptime no service password−encryption

hostname C3750G−24T

ip subnet−zero ip routing

no ip domain−lookup

spanning−tree mode pvst

no spanning−tree optimize bpdu transmission spanning−tree extend system−id

interface GigabitEthernet1/0/1

Cisco − Configuring Inter−VLAN Routing with Catalyst 3750 Series Switches in a Stacked Configuration

3750 specifications

The Cisco Systems 3750 series is a family of enterprise-class stackable switches that were designed to provide high-performance networking solutions for organizations requiring robust management features, security, and scalability. Known for their reliability and advanced capabilities, the 3750 series is particularly aimed at accommodating the demands of LAN environments in organizations ranging from small businesses to large enterprises.

One of the defining features of the Cisco 3750 series is its StackWise technology. This innovative feature enables the stacking of up to nine switches together, allowing them to function as a single logical unit. This results in simplified management, higher redundancy, and increased scalability. The StackWise technology allows for seamless failover and enhanced bandwidth between the stacked switches.

In terms of performance, the 3750 series supports Layer 2 and Layer 3 switching, offering routing capabilities to handle both traditional and modern network demands. It is equipped with advanced Quality of Service (QoS) features, ensuring that critical applications such as voice and video are prioritized for optimal performance.

The Cisco 3750 also features extensive security capabilities. It incorporates features such as IEEE 802.1X authentication, DHCP snooping, and dynamic ARP inspection to protect against unauthorized access and various network attacks. These enhancements help maintain data integrity and secure communications across the network.

Another noteworthy characteristic of the 3750 series is its support for Power over Ethernet (PoE). PoE allows for the delivery of power over Ethernet cables to connected devices, such as IP phones and wireless access points, facilitating simpler installations and reducing the need for additional power outlets.

The Cisco 3750 series also provides a comprehensive set of management tools. With features like Cisco's Embedded Event Manager (EEM) and extensive SNMP support, network administrators can efficiently monitor and manage network performance, troubleshoot issues, and maintain high availability.

Additionally, the series is compatible with Cisco's IOS software, which provides a rich set of features, including advanced routing protocols, multicast support, and extensive security options, further enhancing the functionality and versatility of the switches.

Overall, the Cisco Systems 3750 series stands out for its stackable design, high-performance features, security capabilities, and management tools, making it a popular choice for organizations looking for dependable and scalable networking solutions.