IP Routing 3

IP Switching

IP Switching (or packet forwarding) encompasses tasks required to forward packets for both Layer 2 and Layer 3, as well as traditional routing. These functions include:

Layer 2 forwarding (switching) based on the Layer 2 destination MAC address

Layer 3 forwarding (routing):

-Based on the Layer 3 destination address

-Replacing destination/source MAC addresses for each hop

-Incrementing the hop count

-Decrementing the time-to-live

-Verifying and recalculating the Layer 3 checksum

If the destination node is on the same subnetwork as the source network, then the packet can be transmitted directly without the help of a router. However, if the MAC address is not yet known to the switch, an Address Resolution Protocol (ARP) packet with the destination IP address is broadcast to get the destination MAC address from the destination node. The IP packet can then be sent directly with the destination MAC address.

If the destination belongs to a different subnet on this switch, the packet can be routed directly to the destination node. However, if the packet belongs to a subnet not included on this switch, then the packet should be sent to a router (with the MAC address of the router itself used as the destination MAC address, and the destination IP address of the destination node). The router will then forward the packet to the destination node via the correct path. The router can also use the ARP protocol to find out the MAC address of the destination node of the next router as necessary.

Note: In order to perform IP switching, the switch should be recognized by other network nodes as an IP router, either by setting it as the default gateway or by redirection from another router via the ICMP process.

When the switch receives an IP packet addressed to its own MAC address, the packet follows the Layer 3 routing process. The destination IP address is checked against the Layer 3 address table. If the address is not already there, the switch broadcasts an ARP packet to all the ports on the destination VLAN to find out the destination MAC address. After the MAC address is discovered, the packet is reformatted and sent out to the destination. The reformat process includes decreasing the Time-To-Live (TTL) field of the IP header, recalculating the IP header checksum, and replacing the destination MAC address with either the MAC address of the destination node or that of the next hop router.

When another packet destined to the same node arrives, the destination MAC can be retrieved directly from the Layer 3 address table; the packet is then reformatted and sent out the destination port. IP switching can be done at wire-speed when the destination address entry is already in the Layer 3 address table.

If the switch determines that a frame must be routed, the route is calculated only during setup. Once the route has been determined, all packets in the current flow are simply switched or forwarded across the chosen path. This takes advantage of

3-205

Page 257
Image 257
Microsoft ES4649, ES4625 manual IP Switching, IP Routing

ES4649, ES4625 specifications

The Microsoft ES4625 and ES4649 are advanced enterprise-grade servers designed to meet the demands of modern data centers. They blend cutting-edge technology with robust performance, making them an ideal choice for businesses that require reliable processing capabilities, enhanced storage solutions, and improved energy efficiency.

One of the standout features of the ES4625 is its powerful processing capability. Equipped with the latest Intel Xeon Scalable processors, the server can handle a significant workload, making it suitable for various applications, including virtualization, cloud computing, and big data analytics. The multi-core architecture allows for efficient parallel processing, thereby improving response times and overall system performance.

On the other hand, the ES4649 offers an even more powerful setup, with the option to support high core counts and a larger memory footprint. This feature is particularly beneficial for enterprises that run demanding applications requiring substantial processing power and memory capacity. Both models support DDR4 memory, ensuring faster data access and overall system efficiency.

Storage adaptability is another key characteristic of these servers. The ES4625 and ES4649 come with multiple drive bays supporting various storage options, including SSDs and traditional HDDs. This flexibility allows organizations to configure their storage according to their specific performance and capacity needs. With support for advanced storage technologies like NVMe, enterprises can achieve unparalleled data transfer speeds, which is crucial for data-intensive applications.

In terms of manageability, both models are equipped with Microsoft’s innovative management tools. The integration of these tools facilitates easy monitoring, troubleshooting, and maintenance of server health and performance, significantly reducing downtime. Moreover, the servers are designed with enhanced security features to protect against unauthorized access and data breaches, ensuring that sensitive information remains secure.

Energy efficiency is another critical characteristic of the ES4625 and ES4649. These servers are designed with power-saving technologies that reduce energy consumption without compromising performance. This aspect is particularly advantageous for businesses looking to lower their operational costs and carbon footprint.

Overall, the Microsoft ES4625 and ES4649 offer a compelling combination of performance, flexibility, and security. They are engineered to support the increasingly complex demands of modern enterprise environments, making them a valuable investment for organizations seeking reliable, high-performing server solutions. Whether for virtualized workloads, cloud services, or heavy data computations, these servers are designed to deliver exceptional results.