Table of Contents
This document describes the features, caveats, and limitations for the Cisco Nexus 5600 Series devices and the Cisco Nexus 2000 Series Fabric Extenders. Use this document in combination with documents listed in the “Obtaining Documentation and Submitting a Service Request” 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 Nexus 5600 and Cisco Nexus 2000 Series release notes: http://www.cisco.com/en/US/docs/switches/datacenter/nexus5600/sw/release/notes/Nexus_5600_Release_Notes.html
Note Table 1 shows the online change history for this document.
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 NX-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 5600 Series device and the Cisco Nexus 2000 Series Fabric Extender (FEX) to improve the performance, scalability, and management of the product line.
The Cisco Nexus 5600 Series includes 10- and 40-Gigabit Ethernet density in energy-efficient compact form factor switches. The Cisco Nexus 5600 Series Layer 2 and Layer 3 set allow for multiple scenarios such as direct-attach 10- and 40-Gigabit Ethernet access and high-density Cisco Fabric Extender (FEX) aggregation deployments, leaf and spine architectures, or compact aggregation to build scalable Cisco Unified Fabric in the data centers.
Cisco Nexus 5600 Series products use the same set of Cisco application-specific integrated circuits (ASICs) and a single software image across the products within the family, which offers feature consistency and operational simplicity. Cisco Nexus 5600 Series switches support robust Layer 2 and Layer 3 functions, industry-leading FEX architecture with Cisco Nexus 2000 and Cisco Nexus B22 Blade FEX, in-service software upgrades (ISSUs), and Cisco FabricPath. Operational efficiency and programmability are enhanced on the Cisco Nexus 5600 Series through advanced analytics, PowerOn Auto Provisioning (POAP), and Python/Tool Command Language (Tcl) scripting.
The Cisco Nexus devices include a family of line-rate, low-latency, lossless 10-Gigabit Ethernet, Cisco Data Center Ethernet, Fibre Channel over Ethernet (FCoE), and native Fibre Channel devices for data center applications.
The Cisco Nexus 2000 Series Fabric Extender (FEX) is a highly scalable and flexible server networking solution that works with the Cisco Nexus 5600 Series devices to provide high-density and low-cost connectivity for server aggregation. Scaling across 1-Gigabit Ethernet, 10-Gigabit Ethernet, and 40-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 device, 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 5600 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 5600 Series Layer 2 Switching Configuration Guide .
Table 2 shows the hardware supported by Cisco NX-OS Release 7.x software.
Cisco Nexus 2248PQ FEX1
Table 3 shows the hardware and Cisco NX-OS Release 7.x software that supports online insertion and removal (OIR).
- New Software Features in Cisco NX-OS Release 7.0(2)N1(1)
- New Hardware Features in Cisco NX-OS Release 7.0(2)N1(1)
- New Software Features in Cisco NX-OS Release 7.0(1)N1(1)
- New Hardware Features in Cisco NX-OS Release 7.0(1)N1(1)
Dynamic FCoE extends the capability and reliability of storage networks by leveraging FabricPath technology to create logical separation of SAN A and SAN B. FCoE VFCs and Interswitch-Links (ISLs) are dynamically configured, simplifying multihop FCoE deployments in leaf-spine topologies.
The Cisco TrustSec security architecture builds secure networks by establishing clouds of trusted network devices. Cisco TrustSec also uses the device information acquired during authentication for classifying, or coloring, the packets as they enter the network. This packet classification is maintained by tagging packets on ingress to the Cisco TrustSec network so that they can be properly identified for the purpose of applying security and other policy criteria along the data path.
- The Server Virtualization Switch (SVS) connection is not deleted during a rollback when NIV is enabled. To resolve this issue, delete the current SVS connection and reapply the original SVS connection. For details, see CSCts17033.
- If you configure a Cisco Nexus 2248TP port to 100 Mbps instead of autonegotiation, then autonegotiation does not occur, which is the expected behavior. Both sides of the link should be configured to both hardwired speed or both autonegotiate.
- 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 workaround.
- In large-scale configurations, some Cisco Nexus 2000 Series Fabric Extenders might 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 5600 Series switch, 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 2148 Fabric Extender does not support frames with the dot1q 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 configure Multiple Spanning Tree (MST) on a Cisco Nexus 5600 Series switch, avoid partitioning the network into a large number of regions.
- By design, vEth interfaces do not share the underlying behavior of a vPC port. As a result, a VLAN is not suspended when the peer switch suspends it. For example, when you shut a VLAN on a primary switch, the VLAN continues to be up on the secondary switch when the vEth interface is on a FEX. When the VLAN on the primary switch goes down, the VLAN on the vEth interface on the primary is suspended, but the vEth on the secondary switch remains up because it is an active VLAN on the secondary switch.
- The packet length in the IP GRE header of a packet exiting from the switch is not equal to the MTU value configured in the ERSPAN source session. This is true for SPAN or ERSPAN. The Cisco Nexus 5600 switch terminates in multiples of 16 bytes. If MTU is configured as 100 bytes, then the actual truncated packet is 96 bytes.
- Unknown unicast packets in FabricPath ports are counted as multicast packets in interface counters. This issue occurs when unknown Unicast packets are sent and received with a reserved multicast address (that floods to a VLAN) in the outer FabricPath header, and the Cisco Nexus 5600 Series switch increments the interface counter based on the outer FabricPath header. As a result, Multicast counters are incremented. There is no workaround for this issue.
- In an emulated switch setup, an inband keepalive does not work. The following steps are recommended for peer keepalive over SVI when a switch is in FabricPath mode:
- The limit of the table that holds the Router MAC and Virtual MAC entries for determining packet routing or switching is 500 entries. The Virtual MAC entries, the MAC used for HSRP/VRRP that is also programmed in this table, can be shared across multiple Layer 3 interfaces. If SVIs 1–100 all have the same group number configured, just one entry needs to be programmed in this table. We recommend that you configure the same group ID across all or multiple Layer 3 interfaces/SVIs. If multiple group IDs are configured on an Layer 3 interface, we recommend that you configure the same set of group IDs across all or multiple Layer 3 interfaces. This configuration supports HSRP/VRRP on more interfaces.
- The maximum IP MTU that can be set on Layer 3 interfaces running Layer 3 protocols is 9192 because of the internal header used inside the switch. The related network-qos policy must be set to 9216.
- On a Cisco Nexus device, if the SPAN source is a FEX port, the frames will always be tagged when leaving the SPAN destination.
- On a Cisco Nexus 5600 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 5600 switch, if the SPAN source is on an access port on the switch port, 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, an error is displayed on the CLI.
- When a FEX port is configured as a tx-source, the multicast traffic is spanned on all VLANs that the tx-source port is a member of. 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, broadcast non-IGMP Layer-2 multicast frames as well as unknown unicast frames originating from that port might 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.
- With a SPAN on Latency session, FEX ports cannot be configured as source or destination.
In a vPC topology, two Cisco Nexus 5600 switches configured as vPC peer switches need to be configured symmetrically for Layer 3 configurations such as SVIs, a peer gateway, routing protocol and policies, and RACLs.
When a Layer 3 module goes offline, all non-management SVIs are shut down. To maintain connectivity when a Layer 3 module fails, you can configure an SVI as a management SVI using the command management under i nterface vlan . This prevents traffic to the management SVI from passing through the failed Layer 3 module.
- Open Caveats
- Resolved Caveats in Cisco NX-OS Release 7.0(2)N1(1)
- Resolved Caveats in Cisco NX-OS Release 7.0(1)N1(1)
Table 4 lists descriptions of open caveats in Cisco NX-OS Release 7.0(1)N1(1)
The Cisco Management Information Base (MIB) list includes Cisco proprietary MIBs and many other Internet Engineering Task Force (IETF) standard MIBs. These standard MIBs are defined in Requests for Comments (RFCs). To find specific MIB information, you must examine the Cisco proprietary MIB structure and related IETF-standard MIBs supported by the Cisco Nexus 5600 Series switch.
For information on obtaining documentation, using the Cisco Bug Search Tool (BST), submitting a service request, and gathering additional information, see What’s New in Cisco Product Documentation at: http://www.cisco.com/c/en/us/td/docs/general/whatsnew/whatsnew.html .
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