Appendix C Switch Port Functionality

802.1Q Trunking

802.1Q Trunking

A trunk is a point-to-point link between one or more Ethernet switch ports and another networking device, such as a router or a switch. Trunks carry the traffic of multiple VLANs over a single link, and they allow you to extend VLANs across an entire network, as shown in Figure C-2. The IEEE 802.1q protocol is an industry-standard trunking encapsulation.

Figure C-2 802.1Q Trunk Port Application

VLAN1

VLAN2

VLAN1,2,3

VLAN2

VLAN3

VLAN1,2,3

VLAN1,2,3

VLAN1

802.1 q Trunk Port connection Access Port connection

82633

The 802.1Q trunk port is used for VLAN extension from one switch to another 802.1Q-capable switch, and used for an 802.1Q-capable router for inter-VLAN routing. The FESMIC supports both the VLAN extension and inter-VLAN routing.

The 802.1Q uses an internal tagging mechanism. Internal tagging means that a tag is inserted within the frame. Note that on an 802.1Q trunk, one VLAN is not tagged. This VLAN, named the native VLAN, must be configured the same on each side of the trunk. We can deduce to which VLAN a frame belongs when we receive a frame with no tag. The EtherType field identifying the 802.1Q frame is 0x8100. In addition to the 12-bit VLAN-ID, 3 bits are reserved for 802.1P priority tagging, as shown in Figure C-3. Also, note that inserting a tag into a frame that already has the maximum Ethernet size creates a 1522 byte frame, that can be considered a “baby giant” by the receiving equipment.

The FESMIC is capable of 802.1Q tagging, only supporting 802.1Q trunking encapsulation. It does not support the Cisco proprietary ISL encapsulation.

Cisco 3200 Series Router Hardware Reference

 

OL-5816-10

C-3

 

Page 127
Image 127
Cisco Systems 3200 manual 802.1Q Trunking, Figure C-2 802.1Q Trunk Port Application

3200 specifications

Cisco Systems 3200 Series routers are designed to deliver high-performance, reliable networking solutions for enterprise and service provider environments. They are part of Cisco's extensive portfolio that addresses the challenges of modern networking, particularly in connecting remote offices and branch locations efficiently and securely.

One of the standout features of the Cisco 3200 Series is its scalability. The routers support a variety of modular interfaces, allowing organizations to tailor their network infrastructure according to specific needs. This modularity ensures that as businesses grow and their networking requirements evolve, the Cisco 3200 can adapt without necessitating a complete overhaul of existing hardware.

Security is another critical characteristic of the Cisco 3200 routers. They incorporate robust security features such as integrated firewall capabilities, advanced encryption standards, and Virtual Private Network (VPN) support. This ensures that sensitive data transmitted over the network is protected from potential threats, making them ideal for businesses that prioritize security, especially in regulated industries.

Performance-wise, the Cisco 3200 is equipped with advanced processing capabilities, enabling it to handle high data throughput even in demanding environments. This performance is bolstered by the use of Cisco's proprietary technologies, such as Quality of Service (QoS) and traffic shaping, which allow the prioritization of critical applications to ensure seamless connectivity.

The router series also benefits from Cisco's extensive software ecosystem, which includes Cisco IOS (Internetwork Operating System). IOS provides a familiar interface for network administrators, alongside a wealth of features for configuration and management. Furthermore, the Cisco 3200 Series is designed to integrate with Cisco's Application Policy Infrastructure Controller (APIC) and Software-Defined Networking (SDN) solutions, offering enhanced flexibility in managing network resources.

Connectivity options for the Cisco 3200 Series are extensive, offering support for various WAN technologies, including MPLS, LTE, and broadband internet. This versatility enables organizations to choose the best connectivity solutions according to their geographic and operational requirements.

Finally, the Cisco 3200 Series routers are built with reliability in mind. They are designed for high availability and redundancy, ensuring that network services remain uninterrupted in the event of hardware failures or maintenance activities.

In conclusion, Cisco Systems 3200 routers represent a comprehensive networking solution, combining scalability, security, performance, and reliability, making them a preferred choice for organizations looking to enhance their networking infrastructure in a dynamic digital landscape.