Book excerpt from NX-OS and Cisco Nexus Switching

Excerpt from NX-OS and Cisco Nexus Switching: Next-Generation Data Center Architectures.

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  • 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

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