This chapter provides an overview of the Cisco NX-OS software.
The Cisco NX-OS software interoperates with Cisco products that run any variant of the Cisco IOS software. The Cisco NX-OS
software also interoperates with any networking operating system that conforms to the IEEE and RFC compliance standards.
Modular Software Design
The Cisco NX-OS software supports distributed multithreaded processing on symmetric multiprocessors (SMPs), multi-core CPUs,
and distributed data module processors. The Cisco NX-OS software offloads computationally intensive tasks, such as hardware
table programming, to dedicated processors distributed across the data modules. The modular processes are created on demand,
each in a separate protected memory space. Processes are started and system resources are allocated only when you enable a
feature. A real-time preemptive scheduler helps to ensure the timely processing of critical functions.
The Cisco NX-OS software has serviceability functions that allow the device to respond to network trends and events. These
features help you with network planning and improving response times.
Switched Port Analyzer
The Switched Port Analyzer (SPAN) feature allows you to analyze all
traffic between ports (called the SPAN source ports) by nonintrusively
directing the SPAN session traffic to a SPAN destination port that has an
external analyzer attached to it. For more information about SPAN, see the
The Call Home feature continuously monitors hardware and software
components to provide e-mail-based notification of critical system events. A
versatile range of message formats is available for optimal compatibility with
pager services, standard e-mail, and XML-based automated parsing applications.
It offers alert grouping capabilities and customizable destination profiles.You
can use this feature, for example, to directly page a network support engineer,
send an e-mail message to a network operations center (NOC), and employ Cisco
AutoNotify services to directly generate a case with the Cisco Technical
Assistance Center (TAC). For more information about Call Home, see the
Cisco generic online diagnostics (GOLD) verify that hardware and
internal data paths are operating as designed. Boot-time diagnostics,
continuous monitoring, and on-demand and scheduled tests are part of the Cisco
GOLD feature set. GOLD allows rapid fault isolation and continuous system
monitoring. For information about configuring GOLD, see the
Embedded Event Manager
Cisco Embedded Event Manager (EEM) is a device and system management
feature that helps you to customize behavior based on network events as they
happen. For information about configuring EEM, see the
This section describes the manageability features in the Cisco NX-OS software.
Simple Network Management Protocol
The Cisco NX-OS software is compliant with Simple Network Management
Protocol (SNMP) version 1, version 2, and version 3. A large number of MIBs is
supported. For more information about SNMP, see the
Role-Based Access Control
With role-based access control (RBAC), you can limit access to device
operations by assigning roles to users. You can customize access and restrict
it to the users who require it. For more information about RBAC, see the
Cisco NX-OS Software Configuration
This section describes the tools you can use to configure Cisco NX-OS software, and provides an overview of the software
configuration process with links to the appropriate chapters.
Tools for Software Configuration
You can use one of two configuration management tools to configure your
The command-line interface (CLI) can manage Cisco MDS 9000 Family
switches using Telnet, SSH, or a serial connection.
The Cisco MDS 9000 Fabric Manager, a Java-based graphical user
interface, can manage Cisco MDS 9000 Family switches using SNMP.
With the CLI, you can type commands at the switch prompt, and the
commands are executed when you press the
Enter key. The CLI parser provides command help, command
completion, and keyboard sequences that allow you to access previously executed
commands from the buffer history.
Continue reading this document for more information on configuring the
Cisco MDS switch using the CLI.
In a large enterprise network, having one time standard for all
network devices is critical for management reporting and event logging
functions when trying to correlate interacting events logged across multiple
devices. Many enterprise customers with extremely mission-critical networks
maintain their own stratum-1 NTP source.
Time synchronization occurs when several frames are exchanged between
clients and servers. The switches in client mode know the address of one or
more NTP servers. The servers act as the time source and receive client
By configuring an IP address as a peer, the Cisco NX-OS device will
obtain and provide time as required. The peer is capable of providing time on
its own and is capable of having a server configured. If both of these
instances point to different time servers, your NTP service is more reliable.
Even if the active server link is lost, you can still maintain the correct time
due to the presence of the peer.
If an active server fails, a configured peer helps in providing the
NTP time. To ensure backup support if the active server fails, provide a direct
NTP server association and configure a peer.
If you only configure a peer, the most accurate peer takes on the role
of the NTP server and the other peer acts as a peer. Both devices end at the
correct time if they have the correct time source or if they point to the
correct NTP source.
In this configuration, the switches were configured as follows:
Switch-1 IPv4 address-10.10.10.1
Switch-1 NTP configuration
NTP server 10.10.10.10
NTP peer 10.10.10.2
Switch-2 IPv4 address-10.10.10.2
Switch-2 NTP configuration
NTP server 10.10.10.9
NTP peer 10.10.10.1
The Cisco NX-OS software 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.
can enable a feature without
installing its license. The Cisco NX-OS software gives you a grace period that
allows you to try a feature before purchasing its license. You must install the
Advanced Services license package to enable the Cisco TrustSec feature.
For detailed information about Cisco NX-OS software licensing, see the
For information about troubleshooting licensing issues, see the
Quality of Service
The Cisco NX-OS software supports quality of service (QoS) functions
for classification, marking, queuing, policing, and scheduling. Modular QoS CLI
(MQC) supports all QoS features. You can use MQC to provide uniform
configurations across various Cisco platforms. For more information, see the