Cisco Systems 17053 appendix Verifying Physical Connection and Link, ∙ show port modDport

Page 5

2Some third−party NIC cards can fall back to half−duplex operation mode, even though both the switchport and NIC configuration are manually configured for 100 Mbps, full−duplex. This is because NIC autonegotiation link detection still operates when the NIC is manually configured. This causes duplex inconsistency between the switchport and the NIC. Symptoms include poor port performance and frame check sequence (FCS) errors that increment on the switchport. In order to troubleshoot this issue, try to manually configure the switchport to 100 Mbps, half−duplex. If this action resolves the connectivity problems, this NIC issue is the possible cause. Try to update to the latest drivers for your NIC, or contact your NIC card vendor for additional support.

Why Is It That the Speed and Duplex Cannot Be Hardcoded on Only One Link Partner?

As indicated in Table 1, a manual setup of the speed and duplex for full−duplex on one link partner results in a duplex mismatch. This happens when you disable autonegotiation on one link partner while the other link partner defaults to a half−duplex configuration. A duplex mismatch results in slow performance, intermittent connectivity, data link errors, and other issues. If the intent is not to use autonegotiation, both link partners must be manually configured for speed and duplex for full−duplex settings.

Recommended Port Configuration (Autonegotiation or Manual Configuration)

There are many opinions on the subject of autonegotiation. Previously, many engineers advised customers not to use autonegotiation with any switch−connected device. However, improvements in the interoperation of autonegotiation and the maturity of the technology has recently changed the view of autonegotiation and its use. In addition, performance issues due to duplex mismatches, caused by the manual setting of speed and duplex on only one link partner, are more common. Because of these recent issues, the use of autonegotiation is regarded as a valid practice.

EtherChannel and Trunking Between Catalyst Switches and NICs

EtherChannel can be configured dynamically with Port Aggregation Protocol (PAgP), and trunking can also be configured dynamically with Dynamic Trunking Protocol (DTP). Both PAgP and DTP are Cisco proprietary protocols and supported only on Catalyst switches. If you want to configure EtherChannel or trunking between Catalyst switches and NICs, it is recommended that you configure these features statically, as other vendor NICs can potentially not support PAgP and DTP. On Catalyst switches, configure the EtherChannel mode to on and trunking mode to nonegotiate, which disables the PAgP and DTP protocols. If you configure the switch port with auto or desirable mode, it is possible you can not be able to form the EtherChannel or trunk with NICs.

Verifying Physical Connection and Link

When you troubleshoot NIC issues, the first step is to verify physical connectivity. Visual inspection of the switch must show a LINK light indicator when connected to a link partner. In addition, the NIC can also have a LINK light indicator. The Command Line Interface (CLI) of the switch must be checked in ordre to verify physical connectivity. The port in question must show connected for Catalyst OS software and line protocol up for Cisco IOS® Software on the switch.

Example for CatOS − Catalyst 2948G, 2980G, 4000, 5000, and 6000 that Run CatOS Software

∙show port modDport

Switch> (enable) show port 3/1

 

 

 

 

 

Port Name

Status

VLAN

Level

Duplex

Speed

Type

 

−−−−−−−−−−

−−−−−−−−

−−−−−−−

−−−−−−−

−−−−−−−

−−−−−−

−−−−−−−−−−−−−−

3/1

notconnect

1

normal

half

100

100BaseFX

MM

Page 4 Page 6
Image 5
Page 4 Page 6
Contents Prerequisites IntroductionDocument ID RequirementsBackground Information General Troubleshooting for 10/100/1000 Mbps NICsAutonegotiation Valid Configuration Duplex Configuration2Mismatch Correct∙ show port modDport Verifying Physical Connection and Link∙ show interfaces type Verifying Switch Port ConfigurationMaintaining Link Link Up/Down Situations Performance Notes Understanding Data Link Errors∙ Adjust switch jitter tolerance FCS Explanation of CatOS show port Command CountersPossible Causes for Incrementing CatOS Counters Explanation of CatOS show mac Command Counters Sniffer Trace Gigabit Autonegotiation Configuration Table Additional Troubleshooting for 1000BASE−X NICsTeaming of Network Interface Cards Gigabit Autonegotiation No Link to Connected DeviceCatalyst 8510 and 8540 CSR Catalyst 6000 and 6500 SwitchesSet port enable Catalyst 5000 and 5500 SwitchesCatalyst 4000, 2948G, and 2980G Switches Day to once a month. This issue can Catalyst 2950 and 3550 Switches NIC NIC Compatibility and Operation IssuesPage LnkChk to enable. 33921641.2241835 Hardware Panel SystemDevice ManagerPage R2BE/RBE/CBE Physical Interface PHY Control Register Programmable Options Appendix B Understanding How Autonegotiation Works= loopback mode switched on Related Information Networking Professionals Connection Featured Conversations

17053 specifications

Cisco Systems 17053 is a robust and versatile networking solution designed to meet the demands of modern data centers and enterprise environments. This device is part of Cisco's comprehensive portfolio of networking products, offering high performance, reliability, and scalability to help organizations enhance their connectivity and operational efficiency.

One of the main features of the Cisco 17053 is its support for advanced routing protocols, including OSPF, BGP, and EIGRP. These protocols enable seamless communication and data exchange across complex networks, ensuring that information is transmitted swiftly and effectively. This is particularly important for organizations that rely on real-time data and applications, such as financial services or online retail.

In addition to its routing capabilities, the Cisco 17053 boasts powerful security features. It provides robust firewall protection, VPN support, and advanced threat detection and mitigation mechanisms. These security measures help protect sensitive data from unauthorized access and cyber threats, ensuring that organizations can operate safely in today's increasingly interconnected world.

Moreover, the Cisco 17053 is equipped with advanced Quality of Service (QoS) functionalities. This feature allows network administrators to prioritize critical applications and ensure consistent performance even during times of high traffic. By managing bandwidth effectively, organizations can reduce latency and improve user experiences across various applications.

Scalability is another key characteristic of the Cisco 17053. The device can easily integrate into existing networks and expand as organizational needs grow. This modularity allows businesses to adapt their infrastructure without the need for a complete overhaul, saving time and resources.

Additionally, the Cisco 17053 supports various access technologies, including Ethernet and fiber connections, which provide flexibility in deployment. The device is designed to accommodate different network topologies, making it suitable for both small businesses and large enterprises.

Lastly, Cisco offers comprehensive support and services for the 17053, including training resources, technical support, and regular software updates. This dedication to customer service ensures that organizations can maximize their investment and stay ahead in an ever-evolving technological landscape.

In conclusion, the Cisco Systems 17053 is a feature-rich networking solution that combines advanced routing protocols, robust security measures, and exceptional scalability. With its ability to enhance network performance and offer comprehensive support, it stands out as a reliable choice for organizations looking to optimize their networking capabilities.
Top Page Image Contents