Excerpt from NX-OS and Cisco Nexus Switching: Next-Generation Data Center Architectures.
Chapter 1: Introduction to Cisco NX-OS
| Excerpt from NX-OS and Cisco Nexus Switching: Next-Generation Data Center Architectures. | |
By Kevin Corbin, Ron Fuller, and David Jansen Published by Cisco Press ISBN-10: 1-58705-892-8 ISBN-13: 978-1-58705-892-9 | |
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This chapter provides an introduction and overview of NX-OS and a comparison between traditional IOS and NX-OS configurations and terminology. The following sections will be covered in this chapter:
NX-OS Overview
NX-OS User Modes
Management Interfaces
Managing System Files
NX-OS Overview
Cisco built the next-generation data center-class operating system designed for maximum scalability and application availability. The NX-OS data center-class operating system was built with modularity, resiliency, and serviceability at its foundation. NX-OS is based on the industry-proven Cisco Storage Area Network Operating System (SAN-OS) Software and helps ensure continuous availability to set the standard for mission-critical data center environments. The self-healing and highly modular design of Cisco NX-OS enables for operational excellence increasing the service levels and enabling exceptional operational flexibility. Several advantages of Cisco NX-OS include the following:
Unified data center operating system
Robust and rich feature set with a variety of Cisco innovations
Flexibility and scalability
Modularity
Virtualization
Resiliency
IPv4 and IPv6 IP routing and multicast features
Comprehensive security, availability, serviceability, and management features
Key features and benefits of NX-OS include
Virtual device contexts (VDC): Cisco Nexus 7000 Series switches can be segmented into virtual devices based on customer requirements. VDCs offer several benefits such as fault isolation, administration plane, separation of data traffic, and enhanced security.
Virtual Port Channels (vPC): Enables a server or switch to use an EtherChannel across two upstream switches without an STP-blocked port to enable use of all available uplink bandwidth.
Continuous system operation: Maintenance, upgrades, and software certification can be performed without service interruptions due to the modular nature of NX-OS and features such as In-Service Software Upgrade (ISSU) and the capability for processes to restart dynamically.
Security: Cisco NX-OS provides outstanding data confidentiality and integrity, supporting standard IEEE 802.1AE link-layer cryptography with 128-bit Advanced Encryption Standard (AES) cryptography. In addition to CTS, there are many additional security features such as access control lists (ACL) and port-security, for example.
Base services: The default license that ships with NX-OS covers Layer 2 protocols including such features such as Spanning Tree, virtual LANs (VLAN), Private VLANS, and Unidirectional Link Detection (UDLD).
Enterprise Services Package: Provides Layer 3 protocols such as Open Shortest Path First (OSPF), Border Gateway Protocol (BGP), Intermediate System-to-Intermediate System (ISIS), Enhanced Interior Gateway Routing Protocol (EIGRP), Policy-Based Routing (PBR), Protocol Independent Multicast (PIM), and Generic Routing Encapsulation (GRE).
Advanced Services Package: Provides Virtual Device Contexts (VDC), Cisco Trustsec (CTS), and Overlay Transport Virtualization (OTV).
Transport Services License: Provides Overlay Transport Virtualization (OTV) and Multiprotocol Label Switching (MPLS) (when available).
Example 1-1 shows the simplicity of installing the NX-OS license file.
Example 1-1 Displaying and Installing the NX-OS License File
! Once a license file is obtained from Cisco.com and copied to flash, it can be in- stalled for the chassis. ! Displaying the host-id for License File Creation on Cisco.com: congo# show license host-idLicense hostid: VDH=TBM14404807! Installing a License File:congo# install license bootflash:license_file.licInstalling license ..donecongo#
Note – NX-OS offers feature testing for a 120-day grace period. Here is how to enable a 120-day grace period:
congo(config)# license grace-period
The feature is disabled after the 120-day grace period begins. The license grace period is enabled only for the default admin VDC, VDC1.
Using the grace period enables customers to test, configure, and fully operate a feature without the need for a license to be purchased. This is particularly helpful for testing a feature prior to purchasing a license.
NX-OS Supported Platforms
NX-OS data center-class operating system, designed for maximum scalability and application availability, has a wide variety of platform support, including the following:
Nexus 7000
Nexus 5000
Nexus 2000
Nexus 1000V
Cisco MDS 9000
Cisco Unified Computing System Manager (UCS)
Nexus 4000
Cisco NX-OS and Cisco IOS Comparison
If you are familiar with traditional Cisco IOS command-line interface (CLI), the CLI for NX-OS is similar to Cisco IOS. There are key differences that should be understood prior to working with NX-OS, however:
When you first log into NX-OS, you go directly into EXEC mode.
NX-OS has a setup utility that enables a user to specify the system defaults, perform basic configuration, and apply a predefined Control Plane Policing (CoPP) security policy.
NX-OS uses a feature-based license model. An Enterprise or Advanced Services license is required depending on the features required.
A 120-day license grace period is supported for testing, but features are automatically removed from the configuration after the expiration date is reached.
NX-OS has the capability to enable and disable features such as OSPF, BGP, and so on via the feature configuration command. Configuration and verification commands are not available until you enable the specific feature.
Interfaces are labeled in the configuration as Ethernet. There aren’t any speed designations in the interface name. Interface speed is dynamically learned and reflected in the appropriate show commands and interface metrics.
NX-OS supports Virtual Device Contexts (VDC), which enable a physical device to be partitioned into logical devices. When you log in for the first time, you are in the default VDC.
The Cisco NX-OS has two preconfigured instances of VPN Routing Forwarding (VRF) by default (management, default). By default, all Layer 3 interfaces and routing protocols exist in the default VRF. The mgmt0 interface exists in the management VRF and is accessible from any VDC. If VDCs are configured, each VDC has a unique IP address for the mgmt0 interface.
Secure Shell version 2 (SSHv2) is enabled by default. (Telnet is disabled by default.)
Default login administrator user is predefined as admin; a password has to be specified when the system is first powered up. With NX-OS, you must enter a username and password; you cannot disable the username and password login. In contrast, in IOS you can simply type a password; you can optionally set the login to require the use of a username.
NX-OS uses a kickstart image and a system image. Both images are identified in the configuration file as the kickstart and system boot variables; this is the same as the Cisco Multilayer Director Switch (MDS) Fibre Channel switches running SAN-OS.
NX-OS removed the write memory command; use the copy running-config startup-config; there is also the alias command syntax.
The default Spanning Tree mode in NX-OS is Rapid-PVST+.
Caution – In NX-OS, you have to enable features such as OSPF, BGP, and CTS; if you remove a feature via the no feature command, all relevant commands related to that feature are removed from the running configuration.
For example, when configuring vty timeouts and session limits, consider Example 1-2, which illustrates the difference between IOS and NX-OS syntax.
Example 1-2 vty Configurations and Session Limits, Comparing the Differences Between Traditional IOS and NX-OS
! IOS:congo#congo(config)# line vty 0 9congo(config)# exec-timeout 15 0congo(config)# logincongo# copy running-config startup-config-----------------------------------------------------------------! NX-OS:congo(config)# line vtycongo(config)# session-limit 10congo(config)# exec-timeout 15congo# copy running-config startup-config
NX-OS User Modes
Cisco NX-OS CLI is divided into command modes, which define the actions available to the user. Command modes are “nested” and must be accessed in sequence. As you navigate from one command mode to another, an increasingly larger set of commands become available. All commands in a higher command mode are accessible from lower command modes. For example, the show commands are available from any configuration command mode. Figure 1-1 shows how command access builds from EXEC mode to global configuration mode.
Figure 1-1
NX-OS Command Access from EXEC Mode to Global Configuration Mode
EXEC Command Mode
When you first log in, Cisco NX-OS Software places you in EXEC mode. As demonstrated in Example 1-3, the commands available in EXEC mode include the show commands that display device status and configuration information, the clear commands, and other commands that perform actions that you do not save in the device configuration.
Example 1-3 Cisco NX-OS EXEC Mode
Congo# show interface ethernet 1/15Ethernet1/15 is down (SFP not inserted) Hardware: 10000 Ethernet, address: 001b.54c2.bbc1 (bia 001b.54c1.e4da) MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA auto-duplex, auto-speed Beacon is turned off Auto-Negotiation is turned off Input flow-control is off, output flow-control is off Switchport monitor is off Last link flapped never Last clearing of “show interface” counters never 30 seconds input rate 0 bits/sec, 0 packets/sec 30 seconds output rate 0 bits/sec, 0 packets/sec Load-Interval #2: 5 minute (300 seconds) input rate 0 bps, 0 pps; output rate 0 bps, 0 pps L3 in Switched: ucast: 0 pkts, 0 bytes - mcast: 0 pkts, 0 bytes L3 out Switched: ucast: 0 pkts, 0 bytes - mcast: 0 pkts, 0 bytes! Output omitted for brevityCongo#
Global Configuration Command Mode
Global configuration mode provides access to the broadest range of commands. The term global indicates characteristics or features that affect the device as a whole. You can enter commands in global configuration mode to configure your device globally or enter more specific configuration modes to configure specific elements such as interfaces or protocols as demonstrated here:
Nx7000# conf tNx7000(config)# interface ethernet 1/15
Interface Configuration Command Mode
One example of a specific configuration mode that you enter from global configuration mode is interface configuration mode. To configure interfaces on your device, you must specify the interface and enter interface configuration mode.
You must enable many features on a per-interface basis. Interface configuration commands modify the operation of the interfaces on the device, such as Ethernet interfaces or management interfaces (mgmt 0).
Example 1-4 demonstrates moving between the different command modes in NX-OS.
Example 1-4 Interface Ethernet1/5 Is a 10Gigabit Ethernet Interface—Show How the Interface Is Designated at Ethernet and Not Interface Ten1/15.
congo# conf tcongo(config)# interface ethernet 1/15congo(config-if)# exitCongo# show interface ethernet 1/15Ethernet1/15 is down (SFP not inserted) Hardware: 10000 Ethernet, address: 001b.54c2.bbc1 (bia 001b.54c1.e4da) MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA auto-duplex, auto-speed Beacon is turned off Auto-Negotiation is turned off Input flow-control is off, output flow-control is off Switchport monitor is off Last link flapped never Last clearing of “show interface” counters never 30 seconds input rate 0 bits/sec, 0 packets/sec 30 seconds output rate 0 bits/sec, 0 packets/sec Load-Interval #2: 5 minute (300 seconds) input rate 0 bps, 0 pps; output rate 0 bps, 0 pps L3 in Switched: ucast: 0 pkts, 0 bytes - mcast: 0 pkts, 0 bytes L3 out Switched: ucast: 0 pkts, 0 bytes - mcast: 0 pkts, 0 bytesCongo#
NX-OS supports different Ethernet interface types such as Gigabit Ethernet and 10-Gigabit Ethernet interfaces. All interfaces are referred to Ethernet; NX-OS does not designate Gigabit or 10-Gigabit Ethernet interfaces. In Example 1-4, interface 1/15 is a 10-Gigabit Ethernet interface.
Management Interfaces
NX-OS has many different type of management interfaces, all of which the following section covers:
Controller Processor (CP)/Supervisor: Has both the management plane and control plane and is critical to the operation of the network.
Connectivity Management Processor (CMP): Provides a second network interface to the device for use even when the CP is not reachable. The CMP interface is used for out-of-band management and monitoring; the CMP interface is independent from the primary operating system.
MGMT0: Provides true out-of-band management through a dedicated interface and VRF to ensure 100 percent isolation from either control plane or data plane. MGMT0 enables you to manage the devices by the IPv4 or IPv6 address on the MGMT0 interface; the mgmt0 interface is a 10/100/1000 Ethernet interface. When implementing Virtual port-channel (vPC), a best practice is to use the MGMT0 interface for the VPC keepalive link.
Telnet: Provides an unsecure management connection to the NX-OS device.
SSH: Provides a secure management connection to the NX-OS device.
Extended Markup Language (XML) management interfaces: Use the XML-based Network Configuration Protocol (NETCONF) that enables management, monitoring, and communication over the interface with an XML management tool or program.
Simple Network Management Protocol (SNMP): Used by management systems to monitor and configure devices via a set of standards for communication over the TCP/IP protocol.
Controller Processor (Supervisor Module)
The Cisco Nexus 7000 series supervisor module is designed to deliver scalable control plane and management functions for the Cisco Nexus 7000 Series chassis. The Nexus 7000 supervisor module is based on an Intel dual-core processor that enables a scalable control plane. The supervisor modules controls the Layer 2 and Layer 3 services, redundancy capabilities, configuration management, status monitoring, power, and environmental management. The supervisor module also provides centralized arbitration to the system fabric for all line cards. The fully distributed forwarding architecture enables the supervisor to support transparent upgrades to higher forwarding capacity-capable I/O and fabric modules. Two supervisors are required for a fully redundant system, with one supervisor module running as the active device and the other in hot standby mode, providing exceptional high-availability features in data center-class products. Additional features and benefits of the Nexus 7000 supervisor modules to meet demanding data center requirements follow:
Active and standby supervisor.
In-Service Software Upgrade (ISSU) with dual supervisor modules.
Virtual output queuing (VoQ), which is a quality of service (QoS)-aware lossless fabric, avoids the problems associated with head-of-line blocking.
USB interfaces that enable access to USB flash memory devices for software image loading and recovery.
Central arbitration that provides symmetrical control of the flow of traffic through the switch fabric helps ensure transparent switchover with no losses.
Segmented and redundant out-of-band provisioning and management paths.
Virtualization of the management plane via Virtual Device Contexts (vDC).
Integrated diagnostics and protocol decoding with an embedded control plane packet analyzer; this is based on the Wireshark open source. (No additional licenses are required.)
Fully decoupled control plane and data plane with no hardware forwarding on the module.
Distributed forwarding architecture, enabling independent upgrades of the supervisor and fabric.
With Central arbitration and VoQ, this enables for Unified Fabric.
Transparent upgrade capacity and capability; designed to support 40-Gigabit and 100-Gigabit Ethernet.
System locator and beacon LEDs for simplified operations.
Dedicated out-of-band management processor for “lights out” management.
Connectivity Management Processor (CMP)
The supervisor incorporates an innovative dedicated connectivity management processor (CMP) to support remote management and troubleshooting of the complete system. The CMP provides a complete out-of-band management and monitoring capability independent from the primary operating system. The CMP enables lights out management of the supervisor module, all modules, and the Cisco Nexus 7000 Series system without the need for separate terminal servers with the associated additional complexity and cost. The CMP delivers the remote control through its own dedicated processor, memory, and boot flash memory and a separate Ethernet management port. The CMP can reset all system components, including power supplies; it can also reset the host supervisor module to which it is attached, enabling a complete system restart.
The CMP offer many benefits, including the following:
Dedicated processor and memory, and boot flash.
The CMP interface can reset all the system components, which include power, supervisor module, and system restart.
An independent remote system management and monitoring capability enables lights out management of the system.
Remote monitoring of supervisor status and initiation of resets that removes the need for separate terminal server devices for out-of-band management.
System reset while retaining out-of-band Ethernet connectivity, which reduces the need for onsite support during system maintenance.
Capability to remotely view boot-time messages during the entire boot process.
Capability to initiate a complete system power shutdown and restart, which eliminates the need for local operator intervention to reset power for devices.
Login authentication, which provides secure access to the out-of-band management environment.
Access to supervisor logs that enables rapid detection and prevention of potential system problems.
Capability to take full console control of the supervisor.
Complete control is delivered to the operating environment.
Example 1-5 shows how to connect to the CMP interface and the available show commands available from the CMP interface. Also, note the escape sequence of “~,” to get back to the main NX-OS interface. You can also connect from the CMP back to the CP module.
Example 1-5 Connecting to the CMP Interface, Displaying Available show Commands
N7010-1# attach cmpConnectedEscape character is ‘~,’ [tilde comma]N7010-1-cmp5 login: adminPassword:Last login: Tue Aug 11 23:58:12 2009 on ttyS1N7010-1-cmp5# attach cpThis command will disconnect the front-panel console on this supervisor, and will clear all console attach sessions on the CP - proceed(y/n)? yN7010-1#N7010-1# attach cmpConnectedEscape character is ‘~,’ [tilda comma]N7010-1-cmp5 login: adminPassword:Last login: Wed Aug 12 00:06:12 2009 on ttyS1N7010-1-cmp5# show ? attach Serial attach/monitor processes clock Display current date cores Show all core dumps for CMP cp Show CP status information hardware Show cmp hardware information interface Display interface information line Show cmp line information logging Show logging configuration and contents of logfile logs Show all log files for CMP processes Show cmp processes information running-config Current operating configuration sprom Show SPROM contents ssh SSH information system Show system information users Show the current users logged in the system version Show cmp boot information
Telnet
NX-OS enables for Telnet server and client. The Telnet protocol enables TCP/IP terminal connections to a host. Telnet enables a user at one site to establish a TCP connection to a login server at another site and then passes the keystrokes from one device to the other. Telnet can accept either an IP address or a domain name as the remote device address.
Note – Remember that the Telnet server is disabled by default in NX-OS.
The Telnet server is disabled by default on an NX-OS device. Example 1-6 demonstrates how to enable a Telnet server in NX-OS.
Example 1-6 Enabling a Telnet Server in NX-OS
N7010-1# conf tEnter configuration commands, one per line. End with CNTL/Z.N7010-1(config)# feature telnetN7010-1(config)# show telnet servertelnet service enabledN7010-1(config)# copy running-config startup-config[########################################] 100%
SSH
NX-OS supports SSH Server and SSH Client. Use SSH server to enable an SSH client to make a secure, encrypted connection to a Cisco NX-OS device; SSH uses strong encryption for authentication. The SSH server in Cisco NX-OS Software can interoperate with publicly and commercially available SSH clients. The user authentication mechanisms supported for SSH are Remote Authentication Dial-In User Service (RADIUS), Terminal Access Controller Access Control System Plus (TACACS+), and the use of locally stored usernames and passwords.
The SSH client application enables the SSH protocol to provide device authentication and encryption. The SSH client enables a Cisco NX-OS device to make a secure, encrypted connection to another Cisco NX-OS device or to any other device that runs the SSH server.
SSH requires server keys for secure communications to the Cisco NX-OS device. You can use SSH server keys for the following SSH options:
SSH version 2 using Rivest, Shamir, and Adelman (RSA) public-key cryptography
SSH version 2 using the Digital System Algorithm (DSA)
Be sure to have an SSH server key-pair with the appropriate version before allowing the SSH service. You can generate the SSH server key-pair according to the SSH client version used. The SSH service accepts two types of key-pairs for use by SSH version 2:
The dsa option generates the DSA key-pair for the SSH version 2 protocol.
The rsa option generates the RSA key-pair for the SSH version 2 protocol.
By default, Cisco NX-OS Software generates an RSA key using 1024 bits.
SSH supports the following public key formats:
OpenSSH
IETF Secure Shell (SECSH)
Example 1-7 demonstrates how to enable SSH server and configure the SSH server keys.
Example 1-7 Enabling SSH Server and Configuring SSH Server Keys
N7010-1# conf tEnter configuration commands, one per line. End with CNTL/Z.N7010-1(config)# no feature sshXML interface to system may become unavailable since ssh is disabledN7010-1(config)# ssh key rsa 2048generating rsa key(2048 bits).......generated rsa keyN7010-1(config)# feature sshN7010-1(config)# exitN7010-1# show ssh key**************************************rsa Keys generated:Thu Aug 13 23:33:41 2009ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6+TdX+ABH/mq1gQbfhhsjBmm65ksgfQb3Mb3qbwUbNlcAa6fjJCGdHuf3kJox/hjgPDChJOdkUXHjESlV59OhZP/NHlBrBq0TGRr+hfdAssD3wG5oPkywgM4+bR/ssCzoj6jVG41tGmfPip4pr3dqsMzR21DXSKK/tdj7bipWKy1wSkYQzZwatIVPIXRqTJY7L9a+JqVIJEA0QlJM1l0wZ5YbxccB2GKNKCM2x2BZl4okVgl80CCJg7vmn+8RqIOQ5jNAPNeb9kFw9nsPj/r5xFC1RcSKeQbdYAjItU6cX1TslRnKjlWewCgIa26dEaGdawMVuftgu0uM97VCOxZPQ==bitcount:2048fingerprint:1f:b7:a3:3b:f5:ca:a6:36:19:93:98:c7:37:ba:27:db**************************************could not retrieve dsa key information**************************************N7010-1# show ssh serverssh version 2 is enabledN7010-1(config)# username nxos-admin password C1sc0123!N7010-1(config)# username nxos-admin sshkey ssh-rsaAAAAB3NzaC1yc2EAAAABIwAAAQEA6+TdX+ABH/mq1gQbfhhsjBmm65ksgfQb3Mb3qbwUbNlcAa6fjJCGdHuf3kJox/hjgPDChJOd-kUXHjESlV59OhZP/NHlBrBq0TGRr+hfdAssD3wG5oPkywgM4+bR/ssCzoj6jVG41tGmfPip4pr3dqsMzR21DXSKK/tdj7bip-WKy1wSkYQzZwatIVPIXRqTJY7L9a+JqVIJEA0QlJM1l0wZ5YbxccB2GKNKCM2x2BZl4okVgl80CCJg7vmn+8RqIOQ5jNAPNeb9kFw9nsPj/r5xFC1RcSKeQbdYAjItU6cX1TslRnKjlWewCgIa26dEaGdawMVuftgu0uM97VCOxZPQ==N7010-1(config)# show user-accountuser:admin this user account has no expiry date roles:network-adminuser:nxos-admin this user account has no expiry date roles:network-operator ssh public key: ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6+TdX+ABH/mq1gQbfhhsjBmm65ksgfQb3Mb3qbwUbNlcAa6fjJCGdHuf3kJox/hjgPDChJOd-kUXHjESlV59OhZP/NHlBrBq0TGRr+hfdAssD3wG5oPkywgM4+bR/ssCzoj6jVG41tGmfPip4pr3dqsMzR21DXSKK/tdj7bip-WKy1wSkYQzZwatIVPIXRqTJY7L9a+JqVIJEA0QlJM1l0wZ5YbxccB2GKNKCM2x2BZl4okVgl80CCJg7vmn+8RqIOQ5jNAPNeb9kFw9nsPj/r5xFC1RcSKeQbdYAjItU6cX1TslRnKjlWewCgIa26dEaGdawMVuftgu0uM97VCOxZPQ==N7010-1(config)#N7010-1# copy running-config startup-config[########################################] 100%N7010-1#
XML
NX-OS has a robust XML management interface, which can be used to configure the entire switch. The interface uses the XML-based Network Configuration Protocol (NETCONF) that enables you to manage devices and communicate over the interface with an XML management tool or a program. NETCONF is based on RFC 4741 and the NX-OS implementation requires you to use a Secure Shell (SSH) session for communication with the device.
NETCONF is implemented with an XML Schema (XSD) that enables you to enclose device configuration elements within a remote procedure call (RPC) message. From within an RPC message, you select one of the NETCONF operations that matches the type of command that you want the device to execute. You can configure the entire set of CLI commands on the device with NETCONF.
The XML management interface does not require any additional licensing. XML management is included with no additional charge.
XML/NETCONF can be enabled via a web2.0/ajax browser application that uses XML/NETCONF to pull all statistics off all interfaces on the Nexus 7000 running NX-OS in a dynamically updating table.
Figures 1-2, 1-3, and 1-4 demonstrate sample output from the XML/NETCONF interface.
Figure 1-2
Obtaining NX-OS Real-Time Interface Statistics via NETCONF/XML. The IP Address Entered Is the NX-OS mgmt0 Interface.
Login Results to the NX-OS Devices via NETCONF/XML
Figure 1-4
Results of the Selected Attributes, Such as Speed, Duplex, Errors, Counters, MAC Address. The Page Refreshes Every 10 Seconds.
SNMP
The Simple Network Management Protocol (SNMP) is an application-layer protocol that provides a message format for communication between SNMP managers and agents. SNMP provides a standardized framework and a common language used for the monitoring and management of devices in a network.
SNMP has different versions such as SNMPv1, v2, and v3. Each SNMP version has different security models or levels. Most Enterprise customers are looking to implement SNMPv3 because it offers encryption to pass management information (or traffic) across the network. The security level determines if an SNMP message needs to be protected and authenticated. Various security levels exist within a security model:
noAuthNoPriv: Security level that does not provide authentication or encryption.
authNoPriv: Security level that provides authentication but does not provide encryption.
authPriv: Security level that provides both authentication and encryption.
Cisco NX-OS supports the following SNMP standards:
SNMPv1: Simple community-string based access.
SNMPv2c: RFC 2575-based group access that can be tied into RBAC model.
SNMPv3: Enables for two independent security mechanisms, authentication (Hashed Message Authentication leveraging either Secure Hash Algorithm [SHA-1] or Message Digest 5 [MD5] algorithms) and encryption (Data Encryption Standard [DES] as the default and Advanced Encryption Standard [AES]) to ensure secure communication between NMS station and N7K/NX-OS. Both mechanisms are implemented as demonstrated in Example 1-8.
As NX-OS is truly modular and highly available, the NX-OS implementation of SNMP supports stateless restarts for SNMP. NX-OS has also implemented virtualization support for SNMP; NX-OS supports one instance of SNMP per virtual device context (VDC). SNMP is also VRF-aware, which allows you to configure SNMP to use a particular VRF to reach the network management host.
Example 1-8 demonstrates how to enable SNMPv3 on NX-OS.
Example 1-8 Enabling SNMPv3 on NX-OS
N7010-1# conf tEnter configuration commands, one per line. End with CNTL/Z.N7010-1(config)# snmp-server user NMS auth sha Cisc0123! priv Cisc0123! engineID00:00:00:63:00:01:00:10:20:15:10:03N7010-1(config)# snmp-server host 10.100.22.254 informs version 3 auth NMSN7010-1(config)# snmp-server community public roN7010-1(config)# snmp-server community nxos rwN7010-1(config)# show snmpsys contact:sys location:0 SNMP packets input 0 Bad SNMP versions 0 Unknown community name 0 Illegal operation for community name supplied 0 Encoding errors 0 Number of requested variables 0 Number of altered variables 0 Get-request PDUs 0 Get-next PDUs 0 Set-request PDUs 0 No such name PDU 0 Bad value PDU 0 Read Only PDU 0 General errors 0 Get Responses45 SNMP packets output 45 Trap PDU 0 Too big errors 0 No such name errors 0 Bad values errors 0 General errors 0 Get Requests 0 Get Next Requests 0 Set Requests 0 Get Responses 0 Silent dropsCommunity Group / Access context acl_filter--------- -------------- ------- ----------nxos network-adminpublic network-operator______________________________________________________________ SNMP USERS______________________________________________________________User Auth Priv(enforce) Groups____ ____ _____________ ______admin md5 des(no) network-adminnxos-admin sha des(no) network-operator______________________________________________________________ NOTIFICATION TARGET USERS (configured for sending V3 Inform)______________________________________________________________User Auth Priv____ ____ ____NMS sha des(EngineID 0:0:0:63:0:1:0:10:20:15:10:3)SNMP Tcp Authentication Flag : Enabled.-----------------------------------------------------------------------------------Port Monitor : enabled-----------------------------------------------------------------------------------Policy Name : defaultAdmin status : Not ActiveOper status : Not ActivePort type : All Ports-----------------------------------------------------------------------------------Counter Threshold Interval Rising Threshold event Falling Threshold event In Use------- --------- -------- ---------------- ----- ------------------ --Link Loss Delta 60 5 4 1 4 YesSync Loss Delta 60 5 4 1 4 YesProtocol Error Delta 60 1 4 0 4 YesSignal Loss Delta 60 5 4 1 4 YesInvalid Words Delta 60 1 4 0 4 YesInvalid CRC’s Delta 60 5 4 1 4 YesRX Performance Delta 60 2147483648 4 524288000 4 YesTX Performance Delta 60 2147483648 4 524288000 4 Yes-----------------------------------------------------------------------------------SNMP protocol : Enabled-------------------------------------------------------------------Context [Protocol instance, VRF, Topology]N7010-1# show snmp user______________________________________________________________ SNMP USERS______________________________________________________________User Auth Priv(enforce) Groups____ ____ _____________ ______admin md5 des(no) network-adminnxos-admin sha des(no) network-operator______________________________________________________________ NOTIFICATION TARGET USERS (configured for sending V3 Inform)______________________________________________________________User Auth Priv____ ____ ____NMS sha des(EngineID 0:0:0:63:0:1:0:10:20:15:10:3)N7010-1(config)# exitN7010-1# copy running-config startup-config[########################################] 100%N7010-1#
DCNM
Cisco Data Center Network Manager (DCNM) is a management solution that supports NX-OS devices. DCNM maximizes the overall data center infrastructure uptime and reliability, which improves service levels. Focused on the operational management requirements of the data center, DCNM provides a robust framework and rich feature set that fulfills the switching, application, automation, provisioning, and services needs of today’s data centers and tomorrow’s data center requirements.
DCNM is a client-server application supporting a Java-based client-server application. The DCNM client communicates with the DCNM server only, never directly with managed Cisco NX-OS devices. The DCNM server uses the XML management interface of Cisco NX-OS devices to manage and monitor them. The XML management interface is a programmatic method based on the NETCONF protocol that complements the CLI functionality.
DCNM has a robust configuration and feature support on the NX-OS platform. The following features can be configured, provisioned, and monitored through DCNM enterprise management:
Physical ports
Port channels and virtual port channels (vPC)
Loopback and management interfaces
VLAN network interfaces (sometimes referred to as switched virtual interfaces [SVI])
VLAN and private VLAN (PVLAN)
Spanning Tree Protocol, including Rapid Spanning Tree (RST) and Multi-Instance Spanning Tree Protocol (MST)
Virtual Device Contexts
Gateway Load Balancing Protocol (GLBP) and object tracking
Hot Standby Router Protocol (HSRP)
Access control lists
IEEE 802.1X
Authentication, authorization, and accounting (AAA)
Role-based access control
Dynamic Host Configuration Protocol (DHCP) snooping
Dynamic Address Resolution Protocol (ARP) inspection
IP Source Guard
Traffic storm control
Port security
Hardware resource utilization with Ternary Content Addressable Memory (TCAM) statistics
Switched Port Analyzer (SPAN)
DCNM also includes end-end enterprise visibility including topology views, event browsers, configuration change management, device operating system management, hardware asset inventory, logging, and statistical data collection management.
Managing System Files
Directories can be created on bootflash: and external flash memory (slot0:, usb1:, and usb2:); you can also navigate through these directories and use them for files. Files can be created and accessed on bootflash:, volatile:, slot0:, usb1:, and usb2: file systems. Files can be accessed only on the system: file systems. Debug file system can be used for debug log files specified in the debug logfile command. System image files, from remote servers using FTP, Secure Copy (SCP), Secure Shell FTP (SFTP), and TFTP can also be downloaded.
File Systems
Table 1-1 outlines the parameters for the syntax for specifying a local file system, which is:
filesystem:[//module/]
Table 1-1 Syntax for Specifying a Local File System
File System Name | Module | Description |
Bootflash | sup-active sup-local | Internal CompactFlash memory located on the active supervisor module used for storing image files, configuration files, and other miscellaneous files. The initial default directory is bootflash. |
Bootflash | sup-standby sup-remote | Internal CompactFlash memory located on the standby supervisor module used for storing image files, configuration files, and other miscellaneous files. |
slot0 | Not applicable | External CompactFlash memory installed in a supervisor module used for storing system images, configuration files, and other miscellaneous files. |
volatile | Not applicable | Volatile random-access memory (VRAM) located on a supervisor module used for temporary or pending changes. |
Nvram | Not applicable | Nonvolatile random-access memory (NVRAM) located on a supervisor module used for storing the startup-configuration file. |
Log | Not applicable | Memory on the active supervisor that stores logging file statistics. |
system | Not applicable | Memory on a supervisor module used for storing the running-configuration file. |
debug | Not applicable | Memory on a supervisor module used for debug logs. |
usb1 | Not applicable | External USB flash memory installed in a supervisor module used for storing image files, configuration files, and other miscellaneous files. |
usb2 | Not applicable | External USB flash memory installed in a supervisor module used for storing image files, configuration files, and other miscellaneous files. |
Example 1-9 demonstrates some file system commands and how to copy a file.
Example 1-9 File System Commands/Copying a File
N7010-1# dir bootflash: 311 Jun 20 05:15:05 2009 MDS20090619155920643.lic 309 Jun 20 05:15:56 2009 MDS20090619155929839.lic 2470887 Aug 01 08:13:35 2009 dp42 8533440 Apr 17 23:17:14 2009 lacp_tech_all.log 308249 Aug 01 09:08:39 2009 libcmd.so 134 Jun 19 23:06:53 2009 libglbp.log 175 Jun 20 04:14:22 2009 libotm.log 49152 Jun 19 22:50:53 2009 lost+found/ 87081184 Jan 02 06:21:20 2008 congo-s1-dk9.4.0.2.bin 87755113 Dec 11 13:35:25 2008 congo-s1-dk9.4.0.4.bin 92000595 Apr 16 21:55:19 2009 congo-s1-dk9.4.1.4.bin 92645614 Apr 08 06:08:35 2009 congo-s1-dk9.4.1.5.bin 92004757 Jun 02 04:29:19 2009 congo-s1-dk9.4.1.5E2.bin 99851395 Aug 03 05:17:46 2009 congo-s1-dk9.4.2.0.601.bin 100122301 Aug 12 04:42:13 2009 congo-s1-dk9.4.2.1.bin 9905740 Jan 02 06:21:29 2008 congo-s1-epld.4.0.2.img 9730124 Dec 11 13:42:30 2008 congo-s1-epld.4.0.4.img 23584768 Jan 02 06:21:26 2008 congo-s1-kickstart.4.0.2.bin 23785984 Dec 11 13:34:37 2008 congo-s1-kickstart.4.0.4.bin 24718848 Apr 16 21:52:40 2009 congo-s1-kickstart.4.1.4.bin 25173504 Apr 08 06:00:57 2009 congo-s1-kickstart.4.1.5.bin 23936512 Aug 03 05:03:13 2009 congo-s1-kickstart.4.1.5E2.bin 25333248 Aug 03 05:18:37 2009 congo-s1-kickstart.4.2.0.601.bin 25234944 Aug 12 04:40:52 2009 congo-s1-kickstart.4.2.1.bin 12558 Aug 01 08:51:22 2009 shrun 916893 Apr 17 23:23:03 2009 stp_tech.og 4096 Dec 11 14:04:50 2008 vdc_2/ 4096 Dec 11 14:04:50 2008 vdc_3/ 4096 Dec 11 14:04:50 2008 vdc_4/ 592649 Apr 17 23:18:16 2009 vpc_tech.log 942 Jul 10 09:45:27 2009 wiresharkUsage for bootflash://sup-local 982306816 bytes used 827592704 bytes free 1809899520 bytes totalN7010-1# dir bootflash://sup-remote 12349 Dec 05 02:15:33 2008 7k-1-vdc-all.run 4096 Apr 04 06:45:28 2009 eem/ 18180 Apr 02 23:47:26 2009 eem_script.cfg 99851395 Aug 03 05:20:20 2009 congo-s1-dk9.4.2.0.601.bin 100122301 Aug 12 04:46:18 2009 congo-s1-dk9.4.2.1.bin 19021 Apr 03 21:04:50 2009 eem_script_counters.cfg 19781 Apr 05 23:30:51 2009 eem_script_iptrack.cfg 29104 Jun 19 22:44:51 2009 ethpm_act_logs.log 0 Jun 19 22:44:51 2009 ethpm_syslogs.log 175 Jun 20 04:14:37 2009 libotm.log 49152 Jun 19 22:38:45 2009 lost+found/ 87755113 Apr 07 23:54:07 2009 congo-s1-dk9.4.0.4.bin 92000595 Apr 16 21:55:19 2009 congo-s1-dk9.4.1.4.bin 92645614 Apr 08 06:08:35 2009 congo-s1-dk9.4.1.5.bin 92004757 Jun 02 04:29:19 2009 congo-s1-dk9.4.1.5E2.bin 10993389 Mar 22 04:55:13 2009 congo-s1-epld.4.1.3.33.img 23785984 Apr 07 23:47:43 2009 congo-s1-kickstart.4.0.4.bin 24718848 Apr 16 21:52:40 2009 congo-s1-kickstart.4.1.4.bin 25173504 Apr 08 06:00:57 2009 congo-s1-kickstart.4.1.5.bin 23936512 Jun 02 04:26:35 2009 congo-s1-kickstart.4.1.5E2.bin 25333248 Aug 03 05:19:26 2009 congo-s1-kickstart.4.2.0.601.bin 25234944 Aug 12 04:45:24 2009 congo-s1-kickstart.4.2.1.bin 310 Sep 19 03:58:55 2008 n7k-rhs-1.lic 12699 Jan 23 14:02:52 2009 run_vpc_jan22 11562 Mar 13 07:52:42 2009 startup-robert-cfg 16008 Mar 12 02:02:40 2009 startup-vss-cfg 17315 Mar 19 06:24:32 2009 startup-vss-cfg_roberto_mar18 99 Apr 04 06:51:15 2009 test1 9991 Jun 19 23:12:48 2009 vdc.cfg 4096 Jan 22 13:37:57 2009 vdc_2/ 4096 Jan 22 00:40:57 2009 vdc_3/ 4096 Sep 11 12:54:10 2008 vdc_4/ 111096 Dec 20 04:40:17 2008 vpc.cap 0 Feb 03 08:02:14 2009 vpc_hw_check_disable 18166 Apr 03 03:24:22 2009 vpc_vss_apr02 18223 Apr 02 22:40:57 2009 vss_vpc_apr2Usage for bootflash://sup-remote 863535104 bytes used 946364416 bytes free 1809899520 bytes totalN7010-1# copy bootflash://supbootflash://sup-1/ bootflash://sup-active/ bootflash://sup-remote/bootflash://sup-2/ bootflash://sup-local/ bootflash://sup-standby/N7010-1# copy bootflash://sup-local/congo-s1-epld.4.0.4.img bootflash://sup-remote/congo-s1-epld.4.0.4.imgN7010-1# dir bootflash://sup-remote 12349 Dec 05 02:15:33 2008 7k-1-vdc-all.run 4096 Apr 04 06:45:28 2009 eem/ 18180 Apr 02 23:47:26 2009 eem_script.cfg 19021 Apr 03 21:04:50 2009 eem_script_counters.cfg 19781 Apr 05 23:30:51 2009 eem_script_iptrack.cfg 29104 Jun 19 22:44:51 2009 ethpm_act_logs.log 0 Jun 19 22:44:51 2009 ethpm_syslogs.log 175 Jun 20 04:14:37 2009 libotm.log 49152 Jun 19 22:38:45 2009 lost+found/ 87755113 Apr 07 23:54:07 2009 congo-s1-dk9.4.0.4.bin 92000595 Apr 16 21:55:19 2009 congo-s1-dk9.4.1.4.bin 92645614 Apr 08 06:08:35 2009 congo-s1-dk9.4.1.5.bin 92004757 Jun 02 04:29:19 2009 congo-s1-dk9.4.1.5E2.bin 99851395 Aug 03 05:20:20 2009 congo-s1-dk9.4.2.0.601.bin 100122301 Aug 12 04:46:18 2009 congo-s1-dk9.4.2.1.bin 9730124 Aug 12 22:02:57 2009 congo-s1-epld.4.0.4.img 10993389 Mar 22 04:55:13 2009 congo-s1-epld.4.1.3.33.img 23785984 Apr 07 23:47:43 2009 congo-s1-kickstart.4.0.4.bin 24718848 Apr 16 21:52:40 2009 congo-s1-kickstart.4.1.4.bin 25173504 Apr 08 06:00:57 2009 congo-s1-kickstart.4.1.5.bin 23936512 Jun 02 04:26:35 2009 congo-s1-kickstart.4.1.5E2.bin 25333248 Aug 03 05:19:26 2009 congo-s1-kickstart.4.2.0.601.bin 25234944 Aug 12 04:45:24 2009 congo-s1-kickstart.4.2.1.bin 310 Sep 19 03:58:55 2008 n7k-rhs-1.lic 12699 Jan 23 14:02:52 2009 run_vpc_jan22 11562 Mar 13 07:52:42 2009 startup-robert-cfg 16008 Mar 12 02:02:40 2009 startup-vss-cfg 17315 Mar 19 06:24:32 2009 startup-vss-cfg_roberto_mar18 99 Apr 04 06:51:15 2009 test1 9991 Jun 19 23:12:48 2009 vdc.cfg 4096 Jan 22 13:37:57 2009 vdc_2/ 4096 Jan 22 00:40:57 2009 vdc_3/ 4096 Sep 11 12:54:10 2008 vdc_4/ 111096 Dec 20 04:40:17 2008 vpc.cap 0 Feb 03 08:02:14 2009 vpc_hw_check_disable 18166 Apr 03 03:24:22 2009 vpc_vss_apr02 18223 Apr 02 22:40:57 2009 vss_vpc_apr2Usage for bootflash://sup-remote 873283584 bytes used 936615936 bytes free 1809899520 bytes totalN7010-1#
Configuration Files: Configuration Rollback
The configuration rollback feature enables you to take a snapshot, or checkpoint, of the Cisco NX-OS configuration and then reapply that configuration to your device at any point without having to reload the device. Rollback allows any authorized administrator to apply this checkpoint configuration without requiring expert knowledge of the features configured in the checkpoint.
You can create a checkpoint copy of the current running configuration at any time. Cisco NX-OS saves this checkpoint as an ASCII file that you can use to roll back the running configuration to the checkpoint configuration at a future time. You can create multiple checkpoints to save different versions of your running configuration.
When you roll back the running configuration, you can trigger the following rollback types:
Atomic: Implement the rollback only if no errors occur. This is the default rollback type.
Best-effort: Implement a rollback and skip any errors.
Stop-at-first-failure: Implement a rollback that stops if an error occurs.
When you are ready to roll back to a checkpoint configuration, you can view the changes that will be applied to your current running configuration before committing to the rollback operation. If an error occurs during the rollback operation, you can choose to cancel the operation or ignore the error and proceed with the rollback. If you cancel the operation, Cisco NX-OS provides a list of changes already applied before the error occurred. You need to clean up these changes manually.
Configuration rollback limitations are as follows:
Allowed to create up to ten checkpoint copies per VDC.
You are not allowed to apply a checkpoint file of one VDC into another VDC.
You are not allowed to apply a checkpoint configuration in a nondefault VDC if there is a change in the global configuration portion of the running configuration compared to the checkpoint configuration.
The checkpoint filenames must be 75 characters or less.
You are not allowed to start a checkpoint filename with the word auto.
You cannot name a checkpoint file with summary or any abbreviation of the word summary.
Only one user can perform a checkpoint, rollback, or copy the running configuration to the startup configuration at the same time in a VDC.
After execution of write erase and reload commands, checkpoints are deleted. You can use the clear checkpoint database command to clear out all checkpoint files.
Rollback fails for NetFlow if during rollback you try to modify a record that is programmed in the hardware.
Although rollback is not supported for checkpoints across software versions, users can perform rollback at their own discretion and can use the best-effort mode to recover from errors.
When checkpoints are created on bootflash, differences with the running-system configuration cannot be performed before performing the rollback, and the system reports “No Changes.”
Example 1-10 demonstrates how to create a configuration rollback.
Note – You need to make sure you are in the correct VDC. If you need to change VDCs, use the switchto vdc syntax.
Example 1-10 Creating a Configuration Rollback
N7010-1# checkpoint changes...........DoneN7010-1# show diff rollback-patch checkpoint changes running-configCollecting Running-ConfigGenerating Rollback PatchRollback Patch is EmptyN7010-1# conf tEnter configuration commands, one per line. End with CNTL/Z.N7010-1(config)# no snmp-server user nxos-adminN7010-1(config)# exitN7010-1# show diff rollback-patch checkpoint changes running-configCollecting Running-ConfigGenerating Rollback Patch!!no username nxos-admin sshkey ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6+TdX+ABH/mq1gQbfhhsjBmm65ksgfQb3Mb3qbwUbNlcAa6fjJCGdHuf3kJox/hjgPDChJOd-kUXHjESlV59OhZP/NHlBrBq0TGRr+hfdAssD3wG5oPkywgM4+bR/ssCzoj6jVG41tGmfPip4pr3dqsMzR21DXSKK/tdj7bipWKy1wSkYQzZwatIVPIXRqTJY7L9a+JqVIJEA0QlJM1l0wZ5YbxccB2GKNKCM2x2BZl4okVgl80CCJg7vmn+8RqIOQ5jNAPNeb9kFw9nsPj/r5xFC1RcSKeQbdYAjItU6cX1TslRnKjlWewCgIa26dEaGdawMVuftgu0uM97VCOxZPQ==no username nxos-adminN7010-1# rollback running-config checkpoint changesNote: Applying config in parallel may fail Rollback verificationCollecting Running-ConfigGenerating Rollback PatchExecuting Rollback PatchGenerating Running-config for verificationGenerating Patch for verificationN7010-1# show snmp user nxos-admin______________________________________________________________ SNMP USER______________________________________________________________User Auth Priv(enforce) Groups____ ____ _____________ ______nxos-admin sha des(no) network-operatorYou can also enable specific SNMP traps:N7010-1(config)# snmp-server enable traps eigrpN7010-1(config)# snmp-server enable traps callhomeN7010-1(config)# snmp-server enable traps linkN7010-1(config)# exitN7010-1#
Operating System Files
Cisco NX-OS Software consists of three images:
The kickstart image, contains the Linux kernel, basic drivers, and initial file system.
The system image contains the system software, infrastructure, Layers 4 through 7.
The Erasable Programmable Logic Device (EPLD) image: EPLDs are found on the Nexus 7000 currently shipping I/O modules. EPLD images are not released frequently,; even if an EPLD image is released, the network administrator is not forced to upgrade to the new image. EPLD image upgrades for I/O modules disrupt traffic going through the I/O module. The I/O module powers down briefly during the upgrade. The EPLD image upgrades are performed one module at a time.
On the Nexus 7000 with dual-supervisor modules installed, NX-OS supports in-service software upgrades (ISSU). NX-OS ISSU upgrades are performed without disrupting data traffic. If the upgrade requires EPLD to be installed onto the line cards that causes a disruption of data traffic, the NX-OS software warns you before proceeding so that you can stop the upgrade and reschedule it to a time that minimizes the impact on your network.
NX-OS ISSU updates the following images:
Kickstart image
System image
Supervisor module BIOS
Data module image
Data module BIOS
Connectivity management processor (CMP) image
CMP BIOS
The ISSU process performs a certain sequence of events, as outlined here:
Step 1. | Upgrade the BIOS on the active and standby supervisor modules and the line cards (data cards/nonsupervisor modules). |
Step 2. | Bring up the standby supervisor module with the new kickstart and system images. |
Step 3. | Switch over from the active supervisor module to the upgraded standby supervisor module. |
Step 4. | Bring up the old active supervisor module with the new kickstart image and the new system image. |
Step 5. | Upgrade the CMP on both supervisor modules. |
Step 6. | Perform nondisruptive image upgrade for line card (data cards/nonsupervisor modules), one at a time. |
Step 7. | ISSU upgrade is complete. |
Virtual Device Contexts (VDCs)
The Nexus 7000 NX-OS software supports Virtual Device Contexts (VDCs), VDC(s) allow the partitioning of a single physical Nexus 7000 device into multiple logical devices. This logical separation provides the following benefits:
Administrative and management separation
Change and failure domain isolation from other VDCs
Address, VLAN, VRF, and vPC isolation
Each VDC appears as a unique device and allows for separate Roles-Based Access Control Management (RBAC) per VDC. This enables VDCs to be administered by different administrators while still maintaining a rich, granular RBAC capability. With this functionalit, each administrator can define virtual routing and forwarding instance (VRF) names and VLAN IDs independent of those used in other VDCs safely with the knowledge that VDCs maintain their own unique software processes, configuration, and data-plane forwarding tables.
Each VDC also maintains an individual high-availability (HA) policy that defines the action that the system will take when a failure occurs within a VDC. Depending on the hardware configuration of the system, there are various actions that can be performed. In a single supervisor system, the VDC can be shut down, restarted, or the supervisor can be reloaded. In a redundant supervisor configuration, the VDC can be shut down, restarted, or a supervisor switchover can be initiated.
Note – Refer to Chapter 6, “High Availability,” for additional details.
There are components that are shared between VDC(s), which include the following:
A single instance of the kernel which supports all of the processes and VDCs.
Supervisor modules
Fabric modules
Power supplies
Fan trays
System fan trays
CMP
CoPP
Hardware SPAN resources
Figure 1-5 shows the logical segmentation with VDCs on the Nexus 7000. A common use case is horizontal consolidation to reduce the quantity of physical switches at the data center aggregation layer. In Figure 1-5, there are two physical Nexus 7000 chassis; the logical VDC layout is also shown.
Figure 1-5
Logical Segmentation with VDCs on the Nexus 7000
VDC Configuration
This section shows the required steps to creating a VDC; once the VDC is created, you will assign resources to the VDC. VDC(s) are always created from the default admin VDC context, VDC context 1.
Note – The maximum number of VDCs that can be configured per Nexus 7000 chassis is four; the default VDC (VDC 1) and three additional VDC(s).
Example 1-11 shows how to configure the VDC core on Egypt.
Example 1-11 Creating VDC “core” on Egypt
egypt(config)# vdc coreNote: Creating VDC, one moment please ...egypt# show vdcvdc_id vdc_name state mac------ -------- ----- ----------1 egypt active 00:1b:54:c2:38:c12 core active 00:1b:54:c2:38:c2egypt# show vdc core detailvdc id: 2vdc name: corevdc state: activevdc mac address: 00:1b:54:c2:38:c2vdc ha policy: RESTARTvdc dual-sup ha policy: SWITCHOVERvdc boot Order: 2vdc create time: Mon Feb 22 13:11:59 2010vdc reload count: 1vdc restart count: 0egypt#
Once the VDC is created, you now have to assign physical interfaces to the VDC. Depending on the Ethernet modules installed in the switch, interface allocation is supported as follows:
The 32-port 10-Gigabit Ethernet Module (N7K-M132XP-12), interfaces can be allocated on a per port-group basis; there are eight port-groups. For example, port-group 1 are interfaces e1, e3, e5, e7; port-group 2 are interfaces e2, e4, e6, e8.
The 48-port 10/100/1000 I/O Module (N7K-M148GT-11) can be allocated on a per-port basis.
The 48-port 1000BaseX I/O Module (N7K-M148GS-11) can be allocated on a per-port basis.
A future module, N7K-D132XP-15, interfaces will be allocated per 2 ports per VDC.
Note – It is not possible to virtualize a physical interface and associate the resulting logical interfaces to different VDCs. A supported configuration is to virtualize a physical interface and associate the resulting logical interfaces with different VRFs or VLANs. By default, all physical ports belong to the default VDC.
Example 1-12 demonstrates how to allocate interfaces to a VDC.
Example 1-12 Allocating Interfaces to a VDC
egypt(config)# vdc coreeqypt(config-vdc)# allocate interface Ethernet1/17egypt(config-vdc)# allocate interface Ethernet1/18
To verify the interfaces allocation, enter the show vdc membership command as demonstrated in Example 1-13.
Example 1-13 Verifying Interface Allocation to a VDC
egypt(config-vdc)# show vdc membershipvdc_id: 1 vdc_name: egypt interfaces: Ethernet1/26 Ethernet1/28 Ethernet1/30 Ethernet1/32 Ethernet2/2 Ethernet2/4 Ethernet2/6 Ethernet2/8 Ethernet2/26 Ethernet2/28 Ethernet2/30 Ethernet2/32 Ethernet3/4 Ethernet3/5 Ethernet3/6 Ethernet3/7 Ethernet3/8 Ethernet3/9 Ethernet3/11 Ethernet3/12 Ethernet3/13 Ethernet3/14 Ethernet3/15 Ethernet3/16 Ethernet3/17 Ethernet3/18 Ethernet3/19 Ethernet3/20 Ethernet3/21 Ethernet3/22 Ethernet3/23 Ethernet3/24 Ethernet3/25 Ethernet3/26 Ethernet3/27 Ethernet3/28 Ethernet3/29 Ethernet3/30 Ethernet3/31 Ethernet3/32 Ethernet3/33 Ethernet3/34 Ethernet3/35 Ethernet3/36 Ethernet3/39 Ethernet3/40 Ethernet3/41 Ethernet3/42 Ethernet3/43 Ethernet3/44 Ethernet3/45 Ethernet3/46 Ethernet3/47 Ethernet3/48vdc_id: 2 vdc_name: core interfaces: Ethernet1/17 Ethernet1/18 Ethernet1/19 Ethernet1/20 Ethernet1/21 Ethernet1/22 Ethernet1/23 Ethernet1/24 Ethernet1/25 Ethernet1/27 Ethernet1/29 Ethernet1/31 Ethernet2/17 Ethernet2/18 Ethernet2/19 Ethernet2/20 Ethernet2/21 Ethernet2/22 Ethernet2/23 Ethernet2/24 Ethernet2/25 Ethernet2/27 Ethernet2/29 Ethernet2/31 Ethernet3/1 Ethernet3/2 Ethernet3/3 Ethernet3/10
In addition to interfaces, other physical resources can be allocated to an individual VDC, including IPv4 route memory, IPv6 route memory, port-channels, and SPAN sessions. Configuring these values prevents a single VDC from monopolizing system resources. Example 1-14 demonstrates how to accomplish this.
Example 1-14 Allocating System Resources
egypt(config)# vdc coreegypt(config-vdc)# limit-resource port-channel minimum 32 maximum equal-to-minegypt(config-vdc)# limit-resource u4route-mem minimum 32 maximum equal-to-minegypt(config-vdc)# limit-resource u6route-mem minimum 32 maximum equal-to-minegypt(config-vdc)# limit-resource vlan minimum 32 maximum equal-to-minegypt(config-vdc)# limit-resource vrf minimum 32 maximum equal-to-min
Defining the VDC HA policy is also done within the VDC configuration sub-mode. Use the ha-policy command to define the HA policy for a VDC as demonstrated in Example 1-15.
Example 1-15 Changing the HA Policy for a VDC
egypt(config)# vdc coreeqypt(config-vdc)# ha-policy dual-sup bringdown
The HA policy will depend based on the use-case or VDC role. For example, if you have dual-supervisor modules in the Nexus 7000 chassis or if the VDC role is development/test, the VDC HA policy may be to just shut down the VDC. If the VDC role is for the core and aggregation use case the HA policy would be switchover.
Troubleshooting
The troubleshooting sections introduce basic concepts, methodology, and general troubleshooting guidelines for problems that might occur when configuring and using Cisco NX-OS.
show Commands
Table 1-2 lists sample EXEC commands showing the differences between IOS and NX-OS
Table 1-2 Sample EXEC Commands Showing the Differences Between IOS and NX-OS.
Operation | IOS | NX-OS |
Displays the running configuration | show runningconfig | show runningconfig |
Displays the startup configuration | show startupconfig | show startupconfig |
Displays the status of a specified | show etherchannel # | show port channel # |
portchannel interface | ||
Displays the current boot variables | show boot | show boot |
Displays all environmental parameters | show environment | show environment |
Displays the percentage of fabric utilized per module | show fabric | utilization show hardware fabric- utilization [detail] |
Displays the supervisors high availability status | show redundancy | show system redundancy status |
Displays CPU and memory usage data | show process cpu | show system resources |
Displays specific VRF information | show ip vrf name | show vrf name |
debug Commands
Cisco NX-OS supports an extensive debugging feature set for actively troubleshooting a network. Using the CLI, you can enable debugging modes for each feature and view a real-time updated activity log of the control protocol exchanges. Each log entry has a timestamp and is listed chronologically. You can limit access to the debug feature through the CLI roles mechanism to partition access on a per-role basis. Although the debug commands show real-time information, you can use the show commands to list historical and real-time information.
Caution – Caution Use the debug commands only under the guidance of your Cisco technical support representative because debug commands can impact your network/device performance.
Save debug messages to a special log file, which is more secure and easier to process than sending the debug output to the console.
By using the ? option, you can see the options that are available for any feature. A log entry is created for each entered command in addition to the actual debug output. The debug output shows a timestamped account of the activity that occurred between the local device and other adjacent devices.
You can use the debug facility to track events, internal messages, and protocol errors. However, you should be careful when using the debug utility in a production environment because some options might prevent access to the device by generating too many messages to the console or creating CPU-intensive events that could seriously affect network performance.
You can filter out unwanted debug information by using the debug-filter command. The debug-filter command enables you to limit the debug information produced by related debug commands.
Example 1-16 limits EIGRP hello packet debug information to Ethernet interface 1/1.
Example 1-16 Filtering debug Information
switch# debug-filter ip eigrp interface ethernet 1/1switch# debug eigrp packets hello
Topology
Throughout the book, you see a common topology for demonstration purposes. Figure 1-6 depicts the physical topology.
Figure 1-6
Physical Topology for Book Demonstration Purposes
Further Reading
NX-OS Feature Navigator: https://tinyurl.com/2btvax
NX-OS Nexus 7000 Supported MIB List: https://tinyurl.com/pzh4gg
NX-OS Nexus 5000 Supported MIB List: https://tinyurl.com/q4pqp5
NX-OS Nexus 1000V Supported MIB List: https://tinyurl.com/nu22mx
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