Tag - switch

Switching Layer 2

Layer 2
This layer, known as the switching layer, allows end station addressing and attachment. Because architectures up to Layer 2 allow end station connectivity, it is often practical to construct a Layer 2-only network, providing simple, inexpensive, high-performance connectivity for hundreds or even thousands of end stations. The past five years have seen the extraordinary success of the “flat” network topologies provided by Layer 2 switches connected to other Layer 2 switches or ATM switches.

Layer 2 switching, also called bridging, forwards packets based on the unique Media Access Control (MAC) address of each end station. Data packets consist of both infrastructure content, such as MAC addresses and other information, and end-user content. At Layer 2, generally no modification is required to packet infrastructure content when going between like Layer 1 interfaces, like Ethernet to Fast Ethernet. However, minor changes to infrastructure content?not end-user data content?may occur when bridging between unlike types such as FDDI and Ethernet. Either way, processing impact is minimal and so is configuration complexity.

Layer 2 deployment has seen the most striking infrastructure change over the past decade. Shared Ethernet, represented by particular cable types or contained within shared hubs, offered a very simple, and even more inexpensive, approach for Layer 2. Though still quite popular, shared technology, where all stations use the same bandwidth slice, has very limited scaling capabilities. Depending upon the applications being used, shared networks of more than one hundred users are becoming less common. Many network designers have “tiered” their infrastructure by feeding shared Layer 2 into switched Layer 2 or even Layer 3. Switched Layer 3 apportions each station?or port?its own dedicated bandwidth segment. Recent enhancements at Layer 2 provide packet prioritization capabilities for the application of network policies. The new IEEE 802.1p standard defines Class of Service (CoS) policies capabilities for Layer 2 segments.

Note that Layer 2 does not ordinarily extend beyond the corporate boundary. To connect to the Internet usually requires a router; in other words, scaling a Layer 2 network requires Layer 3 capabilities.

What is the difference between a router and hub or switch?

Question: What is the difference between a router and hub or switch?
Answer: A¬†router is a more sophisticated network device than either a¬†switch or a¬†hub. Like hubs and switches, network routers are typically small, box-like pieces of equipment that multiple computers can connect. Each features a number of “ports” the front or back that provide the connection points for these computers, a connection for electric power, and a number of LED lights to display device status. While routers, hubs and switches all share similiar physical appearance, routers differ substantially in their inner workings.Traditional routers are designed to join multiple area networks (LANs and¬†WANs). On the Internet or on a large corporate network, for example, routers serve as intermediate destinations for network traffic. These routers receive¬†TCP/IP packets, look inside each packet to identify the source and target¬†IP addresses, then forward these packets as needed to ensure the data reaches its final destination.Routers for home networks (often calledbroadband routers) also can join multiple networks. These routers are designed specifically to join the home (LAN) to the Internet (WAN) for the purpose of Internet connection sharing. In contrast, neither hubs nor switches are capable of joining multiple networks or sharing an Internet connection. A home network with only hubs and switches must designate one computer as the gateway to the Internet, and that device must possess two¬†network adapters for sharing, one for the home LAN and one for the Internet WAN. With a router, all home computers connect to the router equally, and it performs the equivalent gateway functions.

Router Switch Hub

Additionally, broadband routers contain several features beyond those of traditional routers. Broadband routers provide DHCP server and proxy support, for example. Most of these routers also offer integrated firewalls. Finally, wired Ethernet broadband routers typically incorporate a built-in Ethernet switch. These routers allow several hubs or switches to be connected to them, as a means to expand the local network to accomodate more Ethernet devices.

In home networking, hubs and switches technically exist only for wired networks. Wi-Fiwireless routers incorporate a built-in access point that is roughly equivalent to a wired switch.

Virtual Local Area Network (VLAN)

Virtual Local Area Network (VLAN)

Virtual Local Area Network (VLAN) is a logical grouping of hosts. This grouping allows them to communicate if they are on the same LAN, irrespective of the physical topology of the network. VLAN offer the ability to group computers together into logical workgroups. This can simplify network administration when connecting clients to servers that are geographically distributed. Typically, VLAN consist of co-workers in the same department but in different locations or a cross functional team working on a joint endeavor.

Virtual Area Network (VLAN)

 

Virtual Local Area Network (VLAN)

Virtual Local Area Network (VLAN) is a logical grouping of hosts. This grouping allows them to communicate if they are on the same LAN, irrespective of the physical topology of the network. VLAN offer the ability to group computers together into logical workgroups. This can simplify network administration when connecting clients to servers that are geographically distributed. Typically, VLAN consist of co-workers in the same department but in different locations or a cross functional team working on a joint endeavor.

 

VLAN Types:

There are two basic types of VLAN:

  1. Tagged: VLAN is based on the IEEE 802.1Q specification. Each packet has a 4-byte tag added to the packet hearer. The switch must support IEEE 802.1Q tagging and be properly configured. Please check your switch documents for the correct switch configuration.
  2. Un-tagged: Or Port-based VLANs are statically configured on the switch. They are transparent to connected devices.

 

Execution Reviews:

  • Many companies software supports maximum of 64 VLANs per network port or team.
  • To set up IEEE VLAN membership (Multiple VLANs), the adapter must be attached to a switch with IEEE 802.1Q VLAN capability.
  • VLAN can co-exist with teams (if the adapter supports both). The team must be defined first, then you can set up your VLAN.
  • You can set up only one untagged VLAN per port or team. You must have at least one tagged VLAN before you can set up an un-tagged VLAN.
  • After creating the VLAN, the adapter associated with the VLAN can have a temporary loss of connectivity.
  • A VLAN cannot be removed if a virtual NIC is bound to it.
  • If VLAN is assigned to an adapter, the Priority and VLAN¬†option on the Advanced properties tab is enabled and cannot be disabled until all VLAN is removed from the adapter.
  • If you change the setting under the Advanced tab for one VLAN, it changes the settings for all VLANS using that port.
  • Advanced Networking Services (ANS) VLANs are not supported on adapters and teams that have VMQ enabled. But, VLAN filtering with VMQ is supported via Microsoft Hyper-V VLAN interface.
  • You can have different VLAN tags on a child partition and its parent. Those settings are separate from one to another, and can be different or the same. The VLAN tag on the parent and child must be the same if you want the parent and child partitions to be able to communicate through that VLAN.

For more information see Microsoft Hyper-V virtual NIC on teams and VLANs.

 

Advantages of VLAN:

  • Improve LAN configuration updates (Adding, Editing, Moves).
  • Improve network performance.
  • Simplicity in your management tasks.
  • Frontier for broadcast storms.
  • Reduce security complications.

 

Before Patch Installation:

 Before Patch Installation (VLAN)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After Patch Installation:

After Patch Installation (VLAN)

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