Chapter 4 Configuring the Address Resolution Protocol

Immediately Refreshing the Bridge Forwarding Table for a MAC Down Event

Immediately Refreshing the Bridge Forwarding Table for a MAC Down Event

By default, when the CSS receives a Down event for a MAC address in the bridge forwarding table, it may not send an ARP request to an IP address associated with that MAC address for up to 60 seconds to refresh the table. During this time, the bridge flows through the CSS to the MAC address could fail.

You can configure the CSS to immediately send an ARP request for an IP address associated with that MAC address, thus immediately repopulating the entries in bridge forwarding table. Use the global configuration mode arp mac-down-immediatecommand.

For example, enter:

(config)# arp mac-down-immediate

Note Under certain network conditions, such as STP convergences, the CSS may appear to be causing an ARP storm.

To reset the default behavior, enter:

(config)# no arp mac-down-immediate

Configuring ARP Timeout

To set the time, in seconds, to hold an ARP resolution result, use the arp timeout command. When you change the timeout value, this value affects only new ARP entries. All previous ARP entries retain the old timeout value. This timeout value affects only dynamic ARP entries. Static ARP entries are permanent and are not affected by this timeout.

The timeout value is the number of seconds the CSS holds an ARP resolution result. To set a timeout value, enter an integer from 60 to 86400 (24 hours) seconds. The default is 14400 seconds (4 hours). If you do not want the ARP entries to time out, enter none or 86401.

For example:

(config)# arp timeout 120

 

Cisco Content Services Switch Routing and Bridging Configuration Guide

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OL-8241-02

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Cisco Systems OL-8241-02 Configuring ARP Timeout, To reset the default behavior, enter, Config# arp mac-down-immediate
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OL-8241-02 specifications

Cisco Systems OL-8241-02 is a significant component of Cisco's extensive portfolio, catering specifically to the needs of enterprise-level networking. This module is designed to provide advanced routing capabilities, aiding organizations in achieving robust connectivity and efficient data transmission across their networks. It is particularly popular among businesses that require reliable performance and scalability.

One of the main features of the OL-8241-02 module is its support for multiple protocols, including OSPF, EIGRP, and BGP, which allows for seamless integration into various network configurations. This flexibility ensures that organizations can adapt to evolving networking demands without undergoing complete infrastructure overhauls. Furthermore, the module includes advanced security features, such as IPsec VPN support and integrated firewall capabilities, enhancing overall network security and protecting sensitive data from potential threats.

Another noteworthy characteristic of the OL-8241-02 is its exceptional performance metrics. With high throughput rates and low latency, the module can handle significant amounts of data traffic without compromising on speed. This efficiency is particularly critical for businesses that rely heavily on real-time data applications, such as video conferencing and online collaboration tools.

The OL-8241-02 also incorporates cutting-edge technologies like Quality of Service (QoS), which prioritizes network traffic based on application requirements. This feature is essential for ensuring that critical applications receive the bandwidth they need, while less critical tasks can be deprioritized during peak usage times. Additionally, the module supports IPv6, which is vital for organizations looking to future-proof their network infrastructure amid the global transition from IPv4.

The ease of management is another highlight of the OL-8241-02, with user-friendly interfaces and compatibility with Cisco's robust management software. This capability allows IT teams to monitor performance metrics, troubleshoot issues, and configure settings with minimal complexity.

In summary, the Cisco Systems OL-8241-02 module stands out for its versatility, performance, and security features. Equipped with the ability to support various protocols, advanced security measures, and efficient traffic management, it proves to be a reliable choice for enterprises aiming to enhance their networking capabilities and ensure seamless operational continuity.
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