Cisco Nexus Software Release 4.2 for Cisco Nexus 7000 Series Switches
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Updated:August 9, 2017
This product bulletin introduces Cisco® NX-OS Software Release 4.2 for Cisco Nexus™ 7000 Series Switches and summarizes the new features it offers.
Cisco NX-OS 4.2 delivers on the design objectives of the Cisco Nexus 7000 Series, providing a rich and comprehensive feature set to address the high demands of mission-critical data centers. It is also used by the Cisco MDS 9000 Series Multilayer Switches, focusing on data center features and protocols, availability, and operational considerations.
Cisco NX-OS 4.2 supports all hardware and software supported in Release 4.1. In addition, Cisco NX-OS 4.2 for the Cisco Nexus 7000 Series now supports several new software features and new and enhanced Gigabit Ethernet optics. The following list summarizes the main software and hardware features new in this release:
• Port profiles
• Layer 2 NetFlow
• Web Cache Communication Protocol (WCCP)
• Virtual device context (VDC) restart
• Green power and cooling enhancements
• Virtual PortChannel (vPC) enhancements
• Dynamic forwarding information base (FIB) ternary content-addressable memory (TCAM) allocation
Cisco NX-OS 4.2 supports all the hardware for the Cisco Nexus 7000 Series previously supported up through Release 4.1. Release 4.2 adds no new hardware support.
Cisco NX-OS 4.2 adds support for Gigabit Ethernet and optics modules, in the M148GS-11 modules for the Cisco Nexus 7000 Series.
Table 1 lists the additional optics supported in Cisco NX-OS 4.2.
Table 1. New Optics Supported in Cisco NX-OS 4.2
Description For Gigabit Ethernet Module (N7K-M148GS-11)
Cisco 1000BASE-T SFP
Cisco 1000BASE-T SFP (NEBS 3 ESD)
Cisco CWDM SFP, where xxxx is the number (8 colors)
1000BASE-DWDM SFP (100-GHz ITU grid); 15xx.yy nm (40 colors)
Cisco NX-OS 4.2 supports all the software features previously supported up through Release 4.1 on the Cisco Nexus 7000 Series. In addition, Release 4.2 supports the new software features described in Table 2. For more detailed information, refer to the Cisco NX-OS 4.2 release notes (see the "For More Information" section).
Table 2. New Software Features in Cisco NX-OS 4.2
A port profile is a container used to define a common set of configuration commands for multiple interfaces.
Layer 2 NetFlow
Layer 2 NetFlow provides the capability to collect traffic statistics based on the packet's Layer 2 header and thus enables source (SRC) and destination (DST) MAC address accounting.
• Enable Port loopback test during line-card bootup; ports that fail the loopback test will be put in the error disabled state
• Standby Fabric loopback test
• Single 10 Gigabit Ethernet line-card support through embedded multi-instance object tracking
• Support for RFC noncompliant Layer 3 devices (load balancers, firewalls, and network-attached storage [NAS])
• 200 VLANs per vPC (LACP enabled)
• Reconvergence latency target of less than 1 second in most failure scenarios
Command-line interface (CLI) enhancements
• Support for better performance polling of load intervals
• Scripting support enhancements
• Additional show commands
Full high-availability support for rollback
This enhancement brings high-availability awareness to the configuration rollback feature.
Generic routing encapsulation (GRE) tunnel with virtual routing and forwarding (VRF) and VDC
This enhancement allows creation of tunnels in VDCs and VRF instances other than the default VDC.
Dynamic FIB TCAM allocation
Cisco NX-OS 4.1 restricts allocation to 56,000 IPv4, 2000 IPv6, and 32,000 multicast routes. This new feature removes the static allocation of TCAM space for IPv4, IPv6, and multicast routes and allows support for increased IPv4, IPv6, and multicast routes on the existing I/O modules.
Multicast control plane enhancements
• Multicast Routing Information Base (MRIB) Multicast FIB Distribution (MFDM) download optimization
• Txlist in Multicast Source Discovery Protocol (MSDP) for scalability
• Txlist in IP for scalability
• IGMP cache on non-designated router for fast convergence
• Policies for multicast configuration (ip pim rp-addr and ip igmp join-group and static-group)
• IGMP group-specific (GS) queries to router ports only
Implemented on per-interface basis, the load-interval command provides a mechanism to the user for configuring the sample interval for statistics collection. This command allows the user to configure a load interval of from 30 to 300 seconds for physical ports, and 60 to 300 seconds for Layer 3 and SVI ports.
Per-command authorization with TACACS
Command-level granularity is supported for user rights. Roles are not supported in this release.
Border Gateway Protocol (BGP) enhancements
• Advertisement map
• Scalability enhancements
• Support for 4-byte autonomous system number (ASN) plain-number format
• Support for 4-byte ASN communities
• Next-hop tracking enhancements
• Graceful low-memory handling
Open Shortest Path First (OSPF) enhancements
• Capability to limit maximum redistributed routes using a CLI command
• Support for link-state advertisement (LSA) generation pacing for external LSAs
• Multi-area adjacency
Enhanced Interior Gateway Routing Protocol
• Redistribution route limits
• Graceful shutdown for router and interface modes
Intermediate System-to-Intermediate System (IS-IS) Protocol enhancements
• Redistribution route limits
• Graceful shutdown for router interface modes
Adds support for the following MIBs:
• ipRouteTable (MIB-II)
• ipAddrTable (MIB-II)
Cisco NX-OS is available in three license levels. A rich feature set is provided with the Base license, which is bundled with the hardware at no extra cost. The Enterprise license enables incremental functions that are applicable to many enterprise deployments. The Advanced LAN Enterprise license enables next-generation functions such as VDCs and Cisco TrustSec. Table 3 summarizes the three packages.
Table 3. License Packages
Provides a rich feature set appropriate for most data center requirements
Provides incremental functions available only with the Enterprise license:
• IP routing
• OSPFv2 and v3 (IPv4 and v6)
• IS-IS Protocol (IPv4)
• BGP (IPv4 and v6)
• EIGRP (IPv4 and v6)
• IP Multicast
• PIM: Sparse, Bidir, Any-Source Multicast (ASM), and Source-Specific Multicast (SSM) modes (IPv4 and v6)
To place an order, visit the Cisco Ordering homepage. To download software, visit the Cisco Software Center. Table 4 provides ordering information.
Table 4. Ordering Information
Cisco NX-OS Enterprise LAN License
Cisco NX-OS Advanced LAN License
Cisco NX-OS 4.2 Software for the Cisco Nexus 7000 Supervisor 1
Cisco Services and Support
Cisco offers a wide range of services to help accelerate your success in deploying and optimizing Cisco Nexus 7000 Series Switches in your data center. Cisco's innovative services are delivered through a unique combination of people, processes, tools, and partners, and are focused on helping you increase operational efficiency and improve your data center network. Cisco Advanced Services uses an architecture-led approach to help you align your data center infrastructure with your business goals and achieve long-term value. Cisco SMARTnet
® Service helps you resolve mission-critical problems with direct access any time to Cisco network experts and award-winning resources. With this service, you can take advantage of the Smart Call Home service capability, which offers proactive diagnostics and real-time alerts on your Cisco Nexus 7000 Series Switches. Spanning the entire network lifecycle, Cisco Services helps protect your investment, optimize network operations, support migration, and strengthen your IT expertise. For more information about Cisco Data Center Services, visit
For More Information
For more information about Cisco NX-OS, visit the product homepage at
http://www.cisco.com/go/nxos or contact your local account representative.