VLANs in the access layer are established by including both sender and receiver MAC addresses in packets sent between computers on local media like copper wire or optical fiber, thus permitting frames to travel over localized routes.
An effective computer network security plan contains five layers, which must all be checked periodically: physical, logical, network application and information security are essential elements to consider in ensuring Data Center and critical system protection.
Core layer
The core layer is the cornerstone of any computer network. It carries large volumes of data at high speeds while connecting multiple end networks together and routing traffic towards and away from WAN connections, traffic aggregation and performance optimization are handled here by devices like routers and multilayer switches.
Modern data centers are much larger than they were ten years ago, now housing rows upon rows of servers that hum and blink constantly. Their connectivity requirements force a transformation in network design and deployment methods.
Additionally, data center networks must support rapid deployment and scaling. For example, new switches may need to be deployed quickly in seconds rather than days; therefore, data center network designs must include protocols which facilitate rapid switching.
Data Center Network Architecture
Modern data centers must accommodate Multitenant Networks that can be rapidly deployed or decommissioned compared to traditional network designs, making for faster network expansion or contraction times and easier management and replacement of individual building blocks as needed. A flexible architecture must also accommodate for any changes in workload demands that arise over time.
Aggregation switches are an integral component of data center network architecture, providing forwarding from Layer 2 to Layer 3. Often two aggregation switches per access switch are installed as redundancies to prevent single points of failure and ensure continuous operation.
Routers in data center networks are responsible for routing both incoming and outgoing traffic between internal networks and external ones, using protocols like BGP to examine packets arriving and determine their optimal path.
Routers
A router is a network device used to move data packets between networks. It operates at the network layer of OSI model and connects local and wide area networks by selecting optimal paths for every packet and managing traffic across its networks. Most households and small offices don’t need routers while larger office spaces typically require one.
Routers connect multiple networks and devices at the same time, while switches only link devices within a single network. The main distinction between them lies in how each operates: routers find the shortest path for every data packet while switches connect devices at physical and Data Link layers; additionally, routers offer QoS, NetFlow and NAT services while switches do not; making routers better suited to larger enterprises.
Switches
Switches connect devices on a local area network (LAN). They forward data packets based on their destination addresses; unlike Ethernet hubs which simply retransmit all connected data regardless of destination address, switches analyze each device’s MAC (media access control) address to match them with ports in their switch table.
Switches come in all kinds, each offering its own advantages and drawbacks. Unmanaged switches are the simplest and least costly choice, easily connecting with no configuration settings necessary – providing Ethernet devices the ability to exchange messages but lacking advanced features which optimize or secure networks.
Managed switches tend to be more costly but offer a range of features such as high-speed performance, enormous port capacity, low latency support for virtualization environments and security protection – features that many growing organizations find advantageous due to their scalability and flexibility.