3 Configuring the Switch

Address Resolution Protocol

If IP routing is enabled (page 3-207),the router uses its routing tables to make routing decisions, and uses Address Resolution Protocol (ARP) to forward traffic from one hop to the next. ARP is used to map an IP address to a physical layer (i.e., MAC) address. When an IP frame is received by this router (or any standards- based router), it first looks up the MAC address corresponding to the destination IP address in the ARP cache. If the address is found, the router writes the MAC address into the appropriate field in the frame header, and forwards the frame on to the next hop. IP traffic passes along the path to its final destination in this way, with each routing device mapping the destination IP address to the MAC address of the next hop toward the recipient, until the packet is delivered to the final destination.

If there is no entry for an IP address in the ARP cache, the router will broadcast an ARP request packet to all devices on the network. The ARP request contains the following fields similar to that shown in this example:

Table 3-16 Address Resolution Protocol

destination IP address

10.1.0.19

destination MAC address

?

 

 

source IP address

10.1.0.253

 

 

source MAC address

00-00-ab-cd-00-00

 

 

When devices receive this request, they discard it if their address does not match the destination IP address in the message. However, if it does match, they write their own hardware address into the destination MAC address field and send the message back to the source hardware address. When the source device receives a reply, it writes the destination IP address and corresponding MAC address into its cache, and forwards the IP traffic on to the next hop. As long as this entry has not timed out, the router will be able forward traffic directly to the next hop for this destination without having to broadcast another ARP request.

Proxy ARP

When a node in the attached subnetwork does not have routing or a default gateway configured, Proxy ARP can be used to forward ARP requests to a remote subnetwork. When the router receives an ARP request for a remote network and Proxy ARP is enabled, it determines if it has the best route to the remote network, and then answers the ARP request by sending its own MAC address to the requesting node. That node then sends traffic to the router, which in turn uses its own routing table to forward the traffic to the remote destination.

Proxy ARP

ARP

request

no routing, no default

gatewayRemote ARP Server

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Microsoft ES4625, ES4649 manual Address Resolution Protocol, Proxy ARP
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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.
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