Cisco Nexus 1000V for Microsoft Hyper-V Troubleshooting Guide

Quick guide from the manual

This guide provides troubleshooting procedures for the Cisco Nexus 1000V for Microsoft Hyper-V. It covers common issues related to installation, upgrades, licensing, high availability, and network configuration. Use the command-line interface (CLI) tools described here to diagnose and resolve network connectivity and performance problems.

Troubleshooting Process

To effectively troubleshoot your network, follow these systematic steps:

1. Gather information: Define the specific symptoms of the problem.
2. Identify potential causes: List all possible factors contributing to the symptoms.
3. Eliminate causes: Systematically test and eliminate potential problems, starting from the most likely, until the symptoms disappear.

Installation and Connectivity

If you encounter issues during installation or host connectivity, verify the following:

• Host in 'Not Responding' state: Launch the Microsoft SCVMM UI, select the server, and refresh the host.
• Missing VMs: Check 'View Dependent Resources' in the SCVMM UI.
• Adding hosts fails (Error 2912): Ensure the Hyper-V Virtual Ethernet Adapter and Switch Extension Adapter are correctly configured. You may need to uninstall these adapters and recreate the virtual switch.
• SCVMM connectivity: Ensure the VSM is reachable from the SCVMM server by checking proxy and firewall settings.

Upgrades and Licensing

For upgrade and licensing issues:

• ISSU failures: Verify HA synchronization state using 'show system redundancy status'. Ensure sufficient space in the 'bootflash:' repository.
• VEM upgrade issues: Ensure the VSM upgrade is performed before the VEM upgrade.
• License issues: Verify license usage with 'show license usage'. Ensure the host ID in the license file matches the ID on the VSM.

High Availability

To troubleshoot high availability (HA) issues:

• Active VSM not seeing standby: Verify roles using 'show system redundancy status'. Check control and management VLAN connectivity.
• Synchronization failures: Ensure both VSMs are running the same software version.
• Both VSMs active: Check for network connectivity problems between the VSMs and the upstream switch.

Ports and Switching

For port and Layer 2 switching issues:

• Port diagnostics: Use 'show interface brief' to check status. Use 'show interface ethernet mod/port counters' to identify synchronization problems.
• Port Security: If a port is disabled due to a security violation, identify the cause using 'show logging | inc PORT-SECURITY'.
• VLAN issues: Ensure the VLAN is active and allowed on the trunk port using 'show interface switchport'.
• Private VLANs: Verify configuration with 'show vlan private-vlan'.

Advanced Network Features

Troubleshooting for advanced features:

• NetFlow: Use 'module vem module-number execute vemcmd show netflow monitor' to verify monitor status.
• ACLs: Use 'module vem module-number execute vemcmd show acl' to list installed ACLs on the VEM.
• QoS: Use 'module vem module-number execute vemcmd show qos policy' to list installed policy maps.
• SPAN: Verify session status with 'show monitor'.
• IGMP Snooping: Use 'show ip igmp snooping groups' to verify multicast group information.
• DHCP/DAI/IPSG: Use 'show ip dhcp snooping binding' to verify IP-to-MAC bindings.

System Diagnostics and Support

For deep diagnostics, use the following tools:

• Ethanalyzer: A command-line protocol analyzer for capturing control-plane traffic.
• Logs: Use 'show logging logfile' to view system messages.
• Technical Support: Before contacting Cisco TAC, collect switch information using 'show tech-support detail' on the VSM and 'vem-support.ps1' on the VEM.