Table Of Contents
Cisco Nexus 5000 Series Switches
Cisco Nexus 2000 Series Fabric Extenders
Online Insertion and Removal Support
Cisco Nexus 2000 Series 10-Gigabit BASE-T Fabric Extenders
Cisco Nexus B22 Blade Fabric Extender for HP (Cisco Nexus B22HP)
Fibre Channel over Ethernet N-Port Virtualization
Data Center Network Manager Release 5.2 Support
Upgrading or Downgrading to a New Release
Upgrade and Downgrade Guidelines
Supported Upgrade and Downgrade Paths
Configuration Synchronization Limitation
Limitations on the Cisco Nexus 5010 and Cisco Nexus 5020
SPAN Limitations on Fabric Extender Ports
Checkpoint and Configuration Rollback Limitation
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2b)
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2a)
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2)
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(1)
Installation and Upgrade Guides
Obtaining Documentation and Submitting a Service Request
Cisco Nexus 5000 Series
and Cisco Nexus 2000 Series Release Notes,
Release 5.0(3)N2(2b), Release 5.0(3)N2(2a), Release 5.0(3)N2(2), Release 5.0(3)N2(1)
Release Date: December 16, 2011
Part Number: OL-25323-02 TN0Current Release: NX-OS Release 5.0(3)N2(2b)Current Release: NX-OS Release 5.0(3)N2(2a)Current Release: NX-OS Release 5.0(3)N2(2)Current Release: NX-OS Release 5.0(3)N2(1)This document describes the features, caveats, and limitations for Cisco Cisco Nexus 5000 Series switches and the Cisco Nexus 2000 Series Fabric Extenders. Use this document in combination with documents listed in the "Related Documentation" section.
Note Release notes are sometimes updated with new information about restrictions and caveats. See the following website for the most recent version of the Cisco Cisco Nexus 5000 Series and Cisco Nexus 2000 Series release notes: http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/release/notes/Nexus_5000_Release_Notes.html
Note Table 1 shows the online change history for this document.
Table 1 Online History Change
Revision Date DescriptionA0
June 13, 2011
Created NX-OS Release 5.0(3)N2(1) release notes.
B0
June 16, 2011
Moved CSCtn64093 to Resolved.
C0
June 22, 2011
Added Online Insertion and Removal Support.
Added Auto-Negotiation Disable to New Software Features section.
D0
July 19, 2011
Added information about Cisco Nexus 2000 Series 10-Gigabit BASE-T Fabric Extenders.
E0
August 2, 2011
Updated Hardware Supported table and added information about Data Center Network Manager Release 5.2 Support.
F0
September 7, 2011
Added CSCto09813 (PSIRT) and CSCts44423.
Moved CSCto23248 to Resolved.
Updated Flex Links section.
G0
September 9, 2011
Created Release Notes for NX-OS Release 5.0(3)N2(2).
H0
September 13, 2011
I0
October 18, 2011
Removed the following caveats from Open Caveats: CSCti14663, CSCti19511, CSCti22121, CSCti45602, CSCti51365, , CSCtj27113, CSCtj29477, CSCtj30588, CSCtj31760, CSCtj44387, CSCtk08499, CSCtk31209, CSCtl51832, CSCtl56923, CSCtl94853, CSCtl99537, CSCtn76099, CSCtn76613, CSCtn82286, CSCtn87115.
Moved the following caveats from Open Caveats to Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(1): CSCtl95221, CSCtn19019, CSCtn57847, CSCtn58324, CSCto50140, CSCtl87240.
J0
October 26, 2011
Added CSCtq13290 to the Cisco NX-OS Release 5.0(3)N2(1) and Release 5.0(3)N2(2) Open Caveats.
K0
October 26, 2011
Created Release Notes for NX-OS Release 5.0(3)N2(2a).
L0
December 16, 2011
Created Release Notes for NX-OS Release 5.0(3)N2(2b).
M0
July 11, 2012
Added the Cisco Nexus B22HP FEX.
N0
July 31, 2012
Contents
This document includes the following sections:
•Upgrading or Downgrading to a New Release
•Obtaining Documentation and Submitting a Service Request
Introduction
The Cisco NX-OS software is a data center-class operating system built with modularity, resiliency, and serviceability at its foundation. Based on the industry-proven Cisco MDS 9000 SAN-OS software, Cisco NX-OS helps ensure continuous availability and sets the standard for mission-critical data center environments. The highly modular design of Cisco NX-OS makes zero-effect operations a reality and enables exceptional operational flexibility.
Several new hardware and software features are introduced for the Cisco Nexus 5000 Series switch and the Cisco Nexus 2000 Series Fabric Extender (FEX) to improve the performance, scalability, and management of the product line. Cisco NX-OS Release 5.0 also supports all hardware and software supported in Cisco NX-OS Software Release 4.2.
Cisco Nexus 5000 Series Switches
The Cisco Nexus 5000 Series switches include a family of line-rate, low-latency, lossless 10-Gigabit Ethernet, Cisco Data Center Ethernet, Fibre Channel over Ethernet (FCoE), and now native Fibre Channel switches for data center applications. The Cisco Nexus 5000 Series includes the Cisco Nexus 5500 Platform and the Cisco Nexus 5000 Platform.
For information about the Cisco Nexus 5000 Series, see the Cisco Nexus 5000 Series and Cisco Nexus 5500 Platform Hardware Installation Guide.
Cisco Nexus 2000 Series Fabric Extenders
The Cisco Nexus 2000 Series Fabric Extender (FEX) is a highly scalable and flexible server networking solution that works with the Cisco Nexus 5000 Series switches to provide high-density and low-cost connectivity for server aggregation. Scaling across 1-Gigabit Ethernet, 10-Gigabit Ethernet, unified fabric, rack, and blade server environments, the FEX is designed to simplify data center architecture and operations.
The FEX integrates with its parent Cisco Nexus 5000 Series switch which allows zero-touch provisioning and automatic configuration. The FEX provides a single point of management that supports a large numbers of servers and hosts that can be configured with the same feature set as the parent Cisco Nexus 5000 Series switch, including security and quality of service (QoS) configuration parameters. Spanning Tree Protocol (STP) is not required between the Fabric Extender and its parent switch, because the Fabric Extender and its parent switch allow you to enable a large multi-path, loop-free, active-active topology.
Software is not included with the Fabric Extender. Cisco NX-OS software is automatically downloaded and upgraded from its parent switch. For information about configuring the Cisco Nexus 2000 FEX, see the "Configuring the Fabric Extender" chapter in the Cisco Nexus 5000 Series Layer 2 Switching Configuration Guide.
System Requirements
This section includes the following topics:
•Online Insertion and Removal Support
Hardware Supported
The Cisco NX-OS software supports the Cisco Nexus 5000 Series. You can find detailed information about supported hardware in the Cisco Nexus 5000 Series Hardware Installation Guide.
Table 2 shows the hardware supported by Cisco NX-OS Release 5.0(x) software.
Table 2 Hardware Supported by Cisco NX-OS Release 5.0(x) Software
Cisco NX-OS Release Support Hardware Part Number 5.0(3)N2(2b)
5.0(3)N2(2a)
5.0(3)N2(2)
5.0(3)N2(1) 5.0(3)N1(1) 5.0(2)N2(1) 5.0(2)N1(1) Cisco Nexus 5000 SeriesCisco Nexus 5596UP switch
N5K-C5596UP-FA
X
X
—
—
Cisco Nexus 5548UP switch
N5K-C5548UP-FA
X
X
—
—
Cisco Nexus 5548P switch
N5K-C5548P-FA
X
X
X
X
Cisco Nexus 5020P switch
N5K-C5020P-BF
X
X
X
X
Cisco Nexus 5010P switch
N5K-C5010P-BF
X
X
X
X
Cisco Nexus 2000 Series
Cisco Nexus B22HP FEX1
N2K-B22HP-P
X
—
—
—
Cisco Nexus 2232TM FEX
N2K-C2232TM-10GE
X
—
—
—
Cisco Nexus 2232PP FEX
N2K-C2232PP-10GE
X
X
X
X
Cisco Nexus 2248TP FEX
N2K-C2248TP-1GE
X
X
X
X
Cisco Nexus 2224TP FEX
N2K-C2224TP-1GE
X
X
X
X
Cisco Nexus 2148T FEX
N2K-C2148T-1GE
X
X
X
X
Expansion Modules
16-port Universal GEM
N55K-M16UP(=)
X
X
—
—
N5596 Layer 3 GEM
N55K-M160L3(=)
X
X
—
—
N5548 Layer 3 daughter card
N55-D160L3(=)
X
X
—
—
16-port SFP+ Ethernet
N55-M16P(=)
X
X
X
X
8- 10 Gigabit Ethernet and 8- 10 Gigabit FCoE ports
N55-M8P8FP(=)
X
X
X
X
Transceivers
Fabric Extender Transceivers10-Gigabit Ethernet SFP (for Cisco Nexus 2000 Series to Cisco Nexus 5000 Series connectivity)
FET-10G(=)
X
X
X
X
SFP+ Optical10-Gigabit Ethernet—short range
SFP-10G-SR(=)
X
X
X
X
10-Gigabit Ethernet—long range
SFP-10G-LR(=)
X
X
X
X
1000BASE-T standard
GLC-T(=)
X
X
X
X
Gigabit Ethernet SFP, LC connector SX transceiver (MMF)
GLC-SX-MM(=)
X
X
X
X
Gigabit Ethernet SFP, LC connector LX/LH transceiver (SMF)
GLC-LH-SM(=)
X
X
X
X
SFP+ Copper10GBASE-CU SFP+ Cable (1 meters)
SFP-H10GB-CU1M(=)
X
X
X
X
10GBASE-CU SFP+ Cable (3 meters)
SFP-H10GB-CU3M(=)
X
X
X
X
10GBASE-CU SFP+ Cable (5 meters)
SFP-H10GB-CU5M(=)
X
X
X
X
10GBASE-CU SFP+ Cable (7 meters)
SFP-H10GB-ACU7M(=)
X
X
X
X
10GBASE-CU SFP+ Cable (10 meters)
SFP-H10GB-ACU10M(=)
X
X
X
X
Fibre Channel8-Gbps Fibre Channel—short wavelength
DS-SFP-FC8G-SW(=)
X
X
X
X
8-Gbps Fibre Channel—long wavelength
DS-SFP-FC8G-LW(=)
X
X
X
X
4-Gbps Fibre Channel—short wavelength
4DS-SFP-FC4G-SW(=)
X
X
X
X
4-Gbps Fibre Channel—long wavelength
4DS-SFP-FC4G-LW(=)
X
X
X
X
Extended Temperature Range1000BASE-T SFP, extended temperature range
SFP-GE-T(=)
X
X
X
X
Gigabit Ethernet SFP, LC connector SX transceiver (MMF), extended temperature range and digital optical monitoring (DOM)
SFP-GE-S(=)
X
X
X
X
Gigabit Ethernet SFP, LC connector LX/LH transceiver (SMF), extended temperature range and DOM
SFP-GE-L(=)
X
X
X
X
Converged Network Adapters
X
X
X
X
Generation-1 (Pre-FIP) CNAs2
X
X
X
X
1 The Cisco Nexus B22HP FEX is supported starting with Cisco NX-OS Release 5.0(3)N2(2).
2 Generation-1 (Pre-FIP) CNAs are supported on the Nexus 5000 Platform switches; however, they are not supported on the Nexus 5500 Series.
Online Insertion and Removal Support
Table 3 shows the hardware and Cisco NX-OS Release 5.0(x) software that supports online insertion and removal (OIR).
New and Changed Features
This section describes the new features introduced in Cisco NX-OS Release 5.0(3)N2(1). This section includes the following topics:
New Hardware Features
This section describes the following new hardware:
•Cisco Nexus 2000 Series 10-Gigabit BASE-T Fabric Extenders
•Cisco Nexus B22 Blade Fabric Extender for HP (Cisco Nexus B22HP)
Cisco Nexus 2000 Series 10-Gigabit BASE-T Fabric Extenders
The new Cisco Nexus 2000 Series 10GBASE-T Fabric Extenders (N2K-C2232TM-10GE and N2K-C2232TF-10GE) are the first 10GBASE-T platform switches in the Cisco Nexus product family.
The new Cisco Nexus 2232TM FEX and Nexus 2232TF FEX offer the following benefits:
•32 1- and 10-Gigabit BASE-T ports.
•8 10-Gigabit Ethernet ports (The Nexus 2232TM FEX requires SFP+ transceivers and the Nexus 2232TF includes 16 FEX transceivers.)
•Category 6, Category 6a, and Category 7 cabling support.
•1 Uplink module that supports 8 10-Gigabit Ethernet fabric interfaces.
•2 Power supplies (AC or DC power supplies).
•1 Fan module with a choice of standard or reversed airflow.
Cisco Nexus B22 Blade Fabric Extender for HP (Cisco Nexus B22HP)
Starting with Cisco NX-OS Release 5.0(3)N2(2), the Cisco Nexus® B22 Blade Fabric Extender for HP (Cisco Nexus B22HP) provides an extension of the Cisco Nexus switch fabric to the HP server edge.
New Software Features
Cisco NX-OS Release 5.0(3)N2(1) includes the following new or changed software features:
•Fibre Channel over Ethernet N-Port Virtualization
•Data Center Network Manager Release 5.2 Support
Fibre Channel over Ethernet N-Port Virtualization
Beginning with Cisco NX-OS Release 5.0(3)N2(1), Fibre Channel over Ethernet N-Port Virtualization (FCoE NPV) is supported on the Cisco Nexus 5000 Series switches. The FCoE NPV feature is an enhanced form of FIP snooping that provides a secure method to connect FCoE-capable hosts to an FCoE-capable FCoE forwarder (FCF) switch. The FCoE NPV feature provides the following benefits:
•FCoE NPV does not have the management and troubleshooting issues that are inherent to managing hosts remotely at the FCF.
•FCoE NPV implements FIP snooping as an extension to the NPV function while retaining the traffic-engineering, VSAN-management, administration and trouble-shooting aspects of NPV.
•FCoE NPV and NPV together allow communication through FC and FCoE ports at the same time. This provides a smooth transition when moving from FC to FCoE topologies.
For more information, see the Cisco Nexus 5000 Series NX-OS SAN Switching Configuration Guide, Release 5.0(3)N2(1).
Flex Links
Beginning with Cisco NX-OS Release 5.0(3)N2(1), Flex Links are supported on Cisco Nexus 5000 Series switches. Flex Links are a pair of a Layer 2 interfaces (switchports or port channels), where one interface is configured to act as a backup to the other. Flex Links are typically configured in service-provider or enterprise networks where customers do not want to run STP. Flex Links provide link-level redundancy that is an alternative to Spanning Tree Protocol (STP). STP is automatically disabled on Flex Links interfaces.
Note To configure flex links, you must remove the LAN_ENTERPRISE_SERVICES_PKG, LAN_BASE_SERVICES_PKG and then reload the switch.
For more information, see the Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)N2(1).
Configurable Hash Polynomial
Beginning with Cisco NX-OS Release 5.0(3)N2(1), the Cisco Nexus 5500 Platform switches support 8 hash polynomials that can be used for compression on the hash-parameters. Depending on variations in the hash parameters for egress traffic flows from a port channel, different polynomials could provide improved load distribution results.
For more information, see the Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)N2(1).
Orphan Port Shutdown
Beginning with Cisco NX-OS Release 5.0(3)N2(1), you can suspend a non-virtual port channel (vPC) port when a vPC secondary peer link goes down. A non-vPC port, also known as an orphaned port, is a port that is not part of a vPC.
For more information, see the Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)N2(1).
Auto-Negotiation Disable
Beginning with Cisco NX-OS Release 5.0(3)N2(1), you can disable auto-negotiation on a switch port. This feature allows you to connect devices that do not support auto-negotiation (for example, certain DWDM multiplexers) to a Cisco Nexus 5000 Series switch.
Licensing
The Cisco NX-OS licensing feature allows you to access premium features on the device after you install the appropriate license for that feature. Any feature not included in a license package is bundled with the Cisco NX-OS software and is provided to you at no extra charge.
You must purchase and install a license for each device.
Note You can enable most features without installing a license. The Cisco NX-OS software provides a grace period for most features during which time you can try out a feature before purchasing its license. The Layer 3 features do not have a grace period and require an installed Layer 3 Base license to use the routing features.
Beginning with Cisco NX-OS Release 5.0(3)N2(1), the FCoE NPV license (FCOE_NPV_PKG) is available to use the FCoE NPV feature.
For more information on licensing, see the Cisco NX-OS Licensing Guide.
Data Center Network Manager Release 5.2 Support
Cisco DCNM is advanced management software that provides comprehensive life cycle management for the data center LAN and SAN.
Cisco DCNM Release 5.2 combines Cisco Fabric Manager, which previously managed SANs, and Cisco DCNM, which previously managed only LANs, into a unified product that can manage a converged data center fabric. As a part of the product merger in Cisco DCNM Release 5.2, the name Cisco DCNM for SAN replaces the name Cisco Fabric Manager. The name Cisco Fabric Manager still applies to Cisco Fabric Manager Release 5.0(x) and all earlier versions.
Cisco DCNM Release 5.2 supports the Cisco Nexus product family including the Cisco Nexus 5000 Series, Cisco MDS 9000 product family, Catalyst 6500 Series, and the Cisco UCS product family.
For information about new DCNM features for the Cisco Nexus 5000 Series switch, see the Cisco DCNM Release Notes, Release 5.2. For Cisco Nexus 5000 Series and DCNM compatibility information, see the Cisco DCNM Release Compatibility Matrix.
Upgrading or Downgrading to a New Release
This section describes the upgrade and downgrade paths that are supported for Cisco NX-OS Release 5.0(3)N2(1) on the Cisco Nexus 5000 Series switch.
This section includes the following topics:
•Upgrade and Downgrade Guidelines
•Supported Upgrade and Downgrade Paths
Upgrade and Downgrade Guidelines
The following guidelines apply to Cisco NX-OS Release 5.0(3)N2(2b), Cisco NX-OS Release 5.0(3)N2(2a), Release 5.0(3)N2(2), and Release 5.0(3)N2(1) for the Cisco Nexus 5000 Series switches:
•Do not change any configuration settings or network settings during the upgrade. Any changes in the network settings may cause a disruptive upgrade.
•Cisco NX-OS Release 5.0(3)N2(2b), Release 5.0(3)N2(2a), Release 5.0(3)N2(2), and Release 5.0(3)N2(1) are ISSU-compatible with NX-OS Release 4.2(1)N1(1) and later releases.
•Downgrading from NX-OS Release 5.0(2) to NX-OS Release 4.2(1) is disruptive.
•Upgrading from NX-OS Release 4.2(1) to NX-OS Release 5.0(2) is a nondisruptive upgrade (ISSU).
•Upgrading from a Cisco NX-OS Release 4.2(1)-based release to Cisco NX-OS Release 5.0(3)N2(2a), Release 5.0(3)N2(2), or Release 5.0(3)N2(1)is nondisruptive.
•Downgrading from Cisco NX-OS Release 5.0(3)N2(2a), Release 5.0(3)N2(2), or Release 5.0(3)N2(1) to a previous release is disruptive.
•When a Layer 3 license is installed, the Cisco Nexus 5500 Platform does not support an ISSU. Hot swapping a Layer 3 module is not supported.
Supported Upgrade and Downgrade Paths
Table 4 shows the upgrade and downgrade possibilities for Cisco NX-OS Release 5.0(3)N2(2b), Release 5.0(3)N2(2a), Release 5.0(3)N2(2a), Release 5.0(3)N2(2), and Release 5.0(3)N2(1):
Upgrading from NX-OS Release 5.0(3)N2(1) to Release 5.0(3)N2(2), Release 5.0(3)N2(2a), or Release 5.0(3)N2(2b) is nondisruptive.
Downgrading from Cisco NX-OS Release 5.0(3)N2(2b), NX-OS Release 5.0(3)N2(2a) or NX-OS Release 5.0(3)N2(2) to NX-OS Release 5.0(3)N2(1) is disruptive.
Limitations
This section describes the limitations for Cisco NX-OS Release 5.0(3)N2(2b), Release 5.0(3)N2(2a), Release 5.0(3)N2(1) and Release 5.0(3)N2(2).
•When upgrading from Cisco NX-OS Release 4.2(1)N1(1) and earlier releases, to any release, the policy description is lost. This problem does not occur when upgrading from Cisco NX-OS Release 4.2(1)N1(1) and later releases. After an upgrade, We recommend that you reconfigure the policy description. For details, see CSCth14225.
•Starting with Cisco NX-OS Release 4.2(1)N2(1), LACP fast timers are supported. If you downgrade to an earlier release that does not support this feature, entering the install all command displays the following warning:
"Configuration not supported - Lacp fast rate is enabled","Use \"lacp rate normal\" on those interfaces"Before downgrading to an earlier release, change the LACP rate to normal. If you ignore the warning and force the installation, then it is possible that the leftover LACP rate fast configuration would still be active with previous releases of software but the behavior would be unpredictable and link flap might occur. We recommend that you change the LACP rate setting to normal. For details, see CSCth93787.
•When an FC SPAN destination port is changed from SD to F mode and back to SD mode on a NPV switch, the port goes into an error-disabled state. Perform a shut/no-shut after the mode change recovers the port. This issue occurs only in NPV mode. For details, see CSCtf87701.
•If you configure a Cisco Nexus 2248TP port to 100 Mbps instead of autonegotiation, autonegotiation does not occur, which is expected behavior. Both sides of the link should be configured to both hardwired speed or both autonegotiate.
no speed—Autonegotiates and advertises all speeds (only full duplex)
speed 1000—Autonegotiates only for a 802.3x pause
speed 100—Does not autonegotiate; pause cannot be advertised. The peer must be set to not autonegotiate and fix at 100 Mbps (similar to the N2248TP)
For details, see CSCte81998.
•Given the implementation of a single CPU ISSU, the STP root on the PVST region with switches on an MST region is not supported. The PVST simulation on the boundary ports go into a PVST SIM inconsistent blocked state that breaks the STP active path. To work around this issue, move all STP roots on the MST region. However, the work around causes a nondisruptive ISSU to fail because Non-Edge Designated Forwarding Ports are required for an ISSU. For additional information, see CSCtf51577. For information topologies that a nondisruptive upgrade is supported, see to the Cisco Nexus 5000 Series NX-OS Upgrade and Downgrade Guide.
•IGMP queries sent in CSCtf94558 are group-specific queries that are sent with the destination IP/MAC address as the group's address.
GS queries are sent for IP address: 224.1.14.1 to 224.1.14.100 [0100.5E01.0E01 to 0100.5E01.0E64]
These are not link-local addresses. By default, they are not flooded by the hardware into the VLAN. They are sent only to the ports that have joined this group.
This is expected behavior during an ISSU.
In another scenario, the IGMP global queries [dest IP 224.0.0.1] get flooded correctly in the VLAN.
Group-specific queries are not forwarded to ports other than the one that joined the group during ISSU. The reason to forward group-specific queries toward hosts is to avoid having them leave the group. However, if a group has not joined the group, then this is not an issue. If there is an interface that has joined the group, then the queries are expected to make it to the host. While the behavior is different when ISSU is not occurring, it is sufficient and works as expected and there is no impact to traffic. For details, see CSCtf94558.
•The meaning of an MTU configuration has changed in Cisco NX-OS Release 4.2(1)N1(1) and earlier releases. In releases earlier than Cisco NX-OS Release 4.2(1)N1(1), the configured MTU included the Ethernet payload and Ethernet headers. In Cisco NX-OS Release 4.2(1)N1(1), the configured MTU includes only the Ethernet payload and not the Ethernet headers. When upgrading or downgrading between Cisco NX-OS Release 4.2(1)N1(1) and earlier releases, Cisco NX-OS automatically converts the configuration to address this semantic change by adding or subtracting 38 to the MTU to address the Ethernet header size.
In a vPC configuration, the MTU per class needs to be consistent on both switches in the vPC domain for the vPC peer link to come up. When upgrading/downgrading a working vPC setup between pre-4.2(1)N1(1) and 4.2(1)N1(1) releases, the MTU is adjusted to make sure that the MCT peer-link always comes up.
However if you add a peer-link between two switches in a vPC domain that are identically configured (MTU in particular) with one switch running Cisco NX-OS Release 4.2(1)N1(1) and another switch running an earlier release, then the vPC peer link does not come up because the MTU is inconsistent between the two switches.
This is not an issue when upgrading or downgrading peer switches in a vPC domain; this is only an issue when adding a peer link between two switches running Cisco NX-OS Release 4.2(1)N1(1) and earlier releases that were not previously in the same vPC domain.
To resolve this issue, upgrade or downgrade one switch to match the version on the other switch and reconfigure the MTU to be consistent on both sides. For details, see CSCtg27538.
•The channel-group configuration is not applied to the Cisco Nexus 2000 Series downlink interface after downgrading to the Cisco NX-OS Release 4.1(3)N1(1) software. This issue occurs if the speed 1000 command is present under the context of the port channel. To work around this issue, reconfigure the channel-group command after the system comes up and reapply the configuration from the saved configuration in the bootflash. For details, see CSCtc06276.
•When a private VLAN port is configured as a TX (egress) SPAN source, the traffic seen at the SPAN destination port is marked with the VLAN of the ingressed frame. There is no work around.
•In large-scale configurations, some Cisco Nexus 2000 Series Fabric Extenders may take up to 3 minutes to appear online after entering the reload command. A configuration can be termed large scale when the maximum permissible Cisco Nexus 2000 Series Fabric Extenders are connected to a Cisco Nexus 5000 Series switch, and all host-facing ports are connected and each host-facing interface has a large configuration (that supports the maximum permissible ACEs per interface).
•The Cisco Nexus 2000 Fabric Extender does not support PVLANs over VLAN trunks used to connect to another switch. The PVLAN trunks are used only on inter-switch links but the FEX ports are only meant to connect to servers. Because it is not a valid configuration to have an isolated secondary VLAN as part of a Fabric Extender port configured as a VLAN trunk, all frames on isolated secondary VLANs are pruned from going out to a FEX.
•Egress scheduling is not supported across the drop/no-drop class. Each Fabric Extender host port does not support simultaneous drop and no drop traffic. Each Fabric Extender host port can support drop or no drop traffic.
•The Cisco Nexus 2148 Fabric Extender does not support frames with the dot1p vlan 0 tag.
•VACLs of more than one type on a single VLAN are unsupported. Cisco NX-OS software supports only a single type of VACL (either MAC, IPv4, or IPv6) applied on a VLAN. When a VACL is applied to a VLAN, it replaces the existing VACL if the new VACL is a different type. For instance, if a MAC VACL is configured on a VLAN and then an IPv6 VACL is configured on the same VLAN, the IPv6 VACL is applied and the MAC VACL is removed.
•A MAC ACL is applied only on non-IP packets. Even if there is a match eth type = ipv4 statement in the MAC ACL, it does not match an IP packet. To avoid this situation, use IP ACLs to apply access control to the IP traffic instead of using a MAC ACL that matches the EtherType to IPv4 or IPv6.
•Multiple boot kickstart statements in the configuration are not supported.
•If you remove an expansion module with Fibre Channel ports, and the cable is still attached, the following FCP_ERRFCP_PORT errors are displayed:
2008 May 14 15:55:43 switch %KERN-3-SYSTEM_MSG: FCP_ERRFCP_PORT: gat_fcp_isr_ip_fcmac_sync_intr@424, jiffies = 0x7add9a:Unknown intr src_id 42 - kernel2008 May 14 15:55:43 switch %KERN-3-SYSTEM_MSG: FCP_ERRFCP_PORT: gat_fcp_isr_ip_fcmac_sync_intr@424, jiffies = 0x7add9a:Unknown intr src_id 41 - kernelThese messages are informational only, and result in no loss of functionality.
Configuration Synchronization Limitation
When you remove a switch profile using the no switch-profile name [all-config | local-config] command, the configuration in the switch profile is immediately removed from the running configuration. This disrupts the configurations that were present in the switch profile. For example, port channel and vPC configurations are disrupted. For current information about this issue, refer to CSCtl87240 and CSCtl87260.
Limitations on the Cisco Nexus 5010 and Cisco Nexus 5020
The limitations on the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch are as follows:
•Traffic going out the Ethernet SPAN destination is always tagged. The SPAN destination can be in the access or trunk mode and frames on the SPAN source port can be tagged or untagged. Frames are always tagged internally as they travel through the system. Information about whether the frame was originally tagged or untagged, as it appeared in the SPAN source, is not preserved in the SPAN destination. The spanned traffic exiting the SPAN destination port always has the VLAN tag on it. The correct VLAN tag is applied on the frame as it goes out the SPAN destination. The only exception is if frames ingress on a SPAN source port on an invalid VLAN. In this case, vlan 0 is applied on a spanned frame.
•Spanned FCoE frames do not preserve original SMAC and DMAC fields. The Ethernet header gets modified as the frame is spanned to the destination. The modified header fields are displayed when monitored on the SPAN destination.
•The CoS value in spanned FCoE frames on the Ethernet SPAN destination port does not match with the CoS value in the SPAN FCoE source frame. The CoS value on the captured SPAN FCoE frame should be ignored.
•The class-fcoe cannot be removed even if Fibre Channel is not enabled on a switch.
•If a port drains traffic at a rate less than 100 Kbps, it is errdisabled in 10 seconds to avoid buffer exhaustion. However, if the drain rate is larger than 100 Kbps, the port may not be consistently errdisabled within 10 seconds which exhaust ingress buffers and discard frames. Use the shut command to disable the slow-draining port.
•The multicast storm control functionality in the Cisco Nexus 5000 Series does not distinguish between IP, non-IP, registered, or unregistered multicast traffic. All multicast traffic is subject to a single-multicast storm control policer when configured.
IGMP Snooping Limitation
On the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch with a Cisco Nexus 2000 Series Fabric Extender (FEX) installed, unregistered IP multicast packets on one VLAN are forwarded to other VLANs where IGMP snooping is disabled. We recommend that you do not disable IGMP snooping on the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch. A static IGMP join can be configured for devices intended to receive IP multicast traffic but not to send IGMP join requests. This limitation applies to the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch only.
SPAN Limitations on Fabric Extender Ports
The SPAN limitations on Fabric Extender ports are as follows:
•On a Cisco Nexus 5000 Series switch, if the SPAN source is a FEX port then the frames will always be tagged when leaving the SPAN destination.
•On a Cisco Nexus 5010 switch or a Nexus 5020 switch, if the SPAN source is an access port on a switch port or FEX port, the spanned frames at the SPAN destination will be tagged.
•On a Cisco Nexus 5010 switch or a Nexus 5020 switch, if the span source is an access port on a switch port or FEX port, the spanned frames at the SPAN destination will be tagged.
•On a Cisco Nexus 5500 Platform switch, if the SPAN source is on an access port on the switch port, then the frames will not be tagged when leaving the SPAN destination.
•Ports on a FEX can be configured as a tx-source in one session only.
If two ports on the same FEX are enabled to be tx-source, the ports need to be in the same session. If you configure a FEX port as a tx-source and another port belonging to the same FEX is already configured as a tx-source on a different SPAN session, then a error is displayed on the CLI.
In the following example, Interface Ethernet100/1/1 on a FEX 100 is already configured as a tx-source on SPAN session-1:
swor28(config-monitor)# show running-config monitorversion 4.0(1a)N2(1)monitor session 1source interface Ethernet100/1/1 txdestination interface Ethernet1/37no shutIf you add an interface Ethernet100/1/2 as a tx-source to a different SPAN session (session-2) the the following error is displayed:
swor28(config)# monitor session 2swor28(config-monitor)# source interface ethernet 100/1/2 txERROR: Eth100/1/2: Ports on a fex can be tx source in one session onlyswor28(config-monitor)#•When a FEX port is configured as a tx-source, the multicast traffic on all VLANs for which the tx-source port is a member, is spanned. The FEX port sends out only multicast packets that are not filtered by IGMP snooping. For example, if FEX ports 100/1/1-12 are configured on VLAN 11 and the switch port 1/5 sends multicast traffic on VLAN 11 in a multicast group, and hosts connected to FEX ports 100/1/3-12 are interested in receiving that multicast traffic (through IGMP), then that multicast traffic goes out on FEX ports 100/1/3-12, but not on 100/1/1-2.
If you configure SPAN Tx on port 100/1/1, although the multicast traffic does not egress out of port 100/1/1, the SPAN destination does receive that multicast traffic, which is due to a design limitation.
•When a FEX port is configured as both SPAN rx-source and tx-source, the broadcast, non-IGMP Layer-2 multicast, and unknown unicast frames originating from that port may be seen twice on the SPAN destination, once on the ingress and once on the egress path. On the egress path, the frames are filtered by the FEX to prevent them from going out on the same port on which they were received. For example, if FEX port 100/1/1 is configured on VLAN 11 and is also configured as SPAN rx-source and tx-source and a broadcast frame is received on that port, the SPAN destination recognizes two copies of the frame, even though the frame is not sent back on port 100/1/1.
•A FEX port cannot be configured as a SPAN destination. Only a switch port can be configured and used as a SPAN destination.
Checkpoint and Configuration Rollback Limitation
When FCoE is enabled, the checkpoint and configuration rollback functionality is disabled.
Layer 3 Limitations
Asymmetric Configuration
In a vPC topology, two Cisco Nexus 5000 switches configured as vPC peer switches need to be configured symmetrically for Layer 3 configurations such as SVIs, Peer Gateway, routing protocol and policies, and RACLs.
Note vPC consistency check does not include Layer 3 parameters.
SVI
When a Layer 3 module goes offline, all SVIs are shutdown.
Upgrading and Downgrading
When a Layer 3 license is installed, the Cisco Nexus 5500 Platform does not support an ISSU. Layer 3 module hot swaps are not supported.
Cisco Nexus 5548P Daughter Card (N55-D160L3)
Before installing a Layer 3 daughter card (N55-D160L3) into a Cisco Nexus 5548P switch, you must upgrade to Cisco NX-OS Release 5.0(3)N1(1b) or NX-OS Release 5.0(3)N1(1c) and then install the card into the chassis.
Caveats
This section includes the open and resolved caveat record numbers for this release. Links are provided to the Bug Toolkit where you can find details about each caveat.
This section includes the following topics:
•Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2b)
•Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2a)
•Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2)
•Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(1)
Open Caveats
Table 9 lists descriptions of open caveats in Cisco NX-OS Release 5.0(3)N2(1) and Release 5.0(3)N2(2).
. The record ID links to the Cisco Bug Toolkit where you can find details about the caveat.
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2b)
Table 7 lists the caveats that are resolved in Cisco NX-OS Release 5.0(3)N2(2b). The caveats may be open in previous Cisco NX-OS releases.
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2a)
Table 7 lists the caveats that are resolved in Cisco NX-OS Release 5.0(3)N2(2a). The caveats may be open in previous Cisco NX-OS releases.
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(2)
Table 8 lists the caveats that are resolved in Cisco NX-OS Release 5.0(3)N2(2). The caveats may be open in previous Cisco NX-OS releases.
Resolved Caveats—Cisco NX-OS Release 5.0(3)N2(1)
Table 9 lists the caveats that are resolved in Cisco NX-OS Release 5.0(3)N2(1). The caveats may be open in previous Cisco NX-OS releases.
Table 9 Cisco NX-OS 5.0(3)N2(1) Resolved Caveats
Record Number Resolved Caveat HeadlineOn a Cisco Nexus 2000 Fabric Extender, the VLANs on a private VLAN host-port error after a vPC peer-link flap.
A switch profile has been removed to display a warning message prior to execution.
On the Cisco Nexus 5010 switch, an error message is displayed after you issue the wrr cos queue command.
When a Cisco Nexus 5548 switch is connected to a N7K-M132XP-12L module on a Nexus 7000 Series device using twinax cables (any version), the connected port goes into an error disabled state due to excessive link flaps.
Sometimes, the configuration does not synchronize when the switch is rebooted.
Messages are not sent to the syslog server (there no file or director).
An NPV switch has dropped FCoE after an ISSU and an OIR GEM.
Packets are not forwarded when an IPSG-enabled access port is made into a trunk.
During a software upgrade on a Cisco Nexus 5000 Series or Nexus 5500 Platform switch, the switch might reload with an fwm process crash.
The no ip igmp snooping mrouter vpc-peer-link command is not supported with FEX in a dual-homed topology.
A gratuitous ARP broadcast storm occurs when multiple vPCs are configured between Cisco Nexus 7000 Series devices and Cisco Nexus 5000 Series switches.
The BPDU loop guard is triggered when a vPC peer link is shut down.
A vulnerability exists in Cisco Nexus 5000 and 3000 Series Switches that may allow traffic to bypass deny statements in access control lists (ACLs) that are configured on the device.
Cisco has released free software updates that address this vulnerability.
A workaround is available to mitigate this vulnerability.
This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20110907-nexus.shtml.
When arp entry for peer-gateway doesn't exist, DHCP relay drops DHCP reply frames to a vPC peer.
On a Cisco Nexus 5000Series switch running Cisco NX-OS Release 5.0(3)N1(1a), the CPU spikes in the PID wwn.
A vPC crash occurs when configuring a value of 9216 in a range of interfaces. This is followed by a reboot on both Nexus 5000 Series peer switches.
On Cisco Nexus 5000 Series Switches and Cisco Nexus 2000 Series Fabric Extenders running in FC switching mode, an SNMP get request causes the fcdomain service to fail.
On a Cisco Nexus 5596UP switch, the show tech-support command causes a service failure and the switch reboots.
Unsupported FEXs are listed in the FEX-type configuration.
A Cisco Nexus 2232 Fabric Extender fan module (N2K-C2232-FAN) is misidentified as N2K-C2232-FAN-B.
After a nondisruptive ISSU, the FCoE manager process may fail.
A Cisco Nexus 5000 Series or Nexus 5500 Platform switch running NX-OS Release 5.0(3)N1(1), NX-OS Release 5.0(3)N1(1a), or NX-OS Release 5.0(3)N1(1b) might crash when you enter the show queuing interface command on a FEX fabric interface which is administratively down.
SFPs are not recognized after an ISSU to NX-OS Release 5.0(3)N2(1).
Related Documentation
Documentation for Cisco Nexus 5000 Series Switches and Cisco Nexus 2000 Series Fabric Extenders is available at the following URL:
http://www.cisco.com/en/US/products/ps9670/tsd_products_support_series_home.html
The following are related Cisco Nexus 5000 Series and Cisco Nexus 2000 Series Fabric Extender documents:
Release Notes
Cisco Nexus 5000 Series and Cisco Nexus 2000 Series Release Notes
Cisco Nexus 5000 Series Switch Release Notes
Configuration Guides
Cisco Nexus 5000 Series Configuration Limits for Cisco NX-OS Release 5.0(3)
Cisco Nexus 5000 Series Configuration Limits for Cisco NX-OS Release 5.0(2)N1(1)
Cisco Nexus 5000 Series Configuration Limits for Cisco NX-OS Release 4.2(1)N1(1) and Release 4.2(1)N2(1)
Cisco Nexus 5000 Series NX-OS Fibre Channel over Ethernet Configuration Guide
Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration Guide
Cisco Nexus 5000 Series NX-OS Multicast Routing Configuration Guide
Cisco Nexus 5000 Series NX-OS Quality of Service Configuration Guide
Cisco Nexus 5000 Series NX-OS SAN Switching Configuration Guide
Cisco Nexus 5000 Series NX-OS Security Configuration Guide
Cisco Nexus 5000 Series NX-OS System Management Configuration Guide
Cisco Nexus 5000 Series NX-OS Unicast Routing Configuration Guide
Cisco Nexus 5000 Series Switch NX-OS Software Configuration Guide
Cisco Nexus 5000 Series Fabric Manager Configuration Guide, Release 3.4(1a)
Cisco Nexus 7000 Series NX-OS Fundamentals Configuration Guide, Release 4.2
Cisco Nexus 2000 Series Fabric Extender Software Configuration Guide
Maintain and Operate Guides
Cisco Nexus 5000 Series NX-OS Operations Guide
Installation and Upgrade Guides
Cisco Nexus 5000 Series and Cisco Nexus 5500 Platform Hardware Installation Guide
Cisco Nexus 2000 Series Hardware Installation Guide
Cisco Nexus 5000 Series NX-OS Software Upgrade and Downgrade Guide, Release 4.2(1)N1(1)
Regulatory Compliance and Safety Information for the Cisco Nexus 5000 Series Switches and Cisco Nexus 2000 Series Fabric Extenders
Licensing Guide
Cisco NX-OS Licensing Guide
Command References
Cisco Nexus 5000 Series Command Reference
Technical References
Cisco Nexus 5000 Series and Cisco Nexus 2000 Series Fabric Extender MIBs Reference
Error and System Messages
Cisco NX-OS System Messages Reference
Troubleshooting Guide
Cisco Nexus 5000 Troubleshooting Guide
Obtaining Documentation and Submitting a Service Request
For information on obtaining documentation, submitting a service request, and gathering additional information, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation:
http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html
Subscribe to the What's New in Cisco Product Documentation as an RSS feed and set content to be delivered directly to your desktop using a reader application. The RSS feeds are a free service. Cisco currently supports RSS Version 2.0.
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