Each device is shipped with the Cisco NX-OS software. The Cisco NX-OS software consists of one NXOS software image. The image filename begins with nxos.

Only this image is required to load the Cisco NX-OS operating system. This image runs on all Cisco Nexus 3600 Series switches.

Note

Starting from Cisco NX-OS Release 10.5(3)F, Cisco NX-OS no longer provides a separate EPLD image. The EPLD image is bundled with the NX-OS images and so the image sizes are correspondingly larger. Until Cisco NX-OS Release 10.5(2)F, Cisco provided separate electronic programmable logic device (EPLD) image upgrades to enhance hardware functionality or to resolve known hardware issues. For more information on EPLD images and the upgrade process, refer to the relevant version of Cisco Nexus 3600 Platform FPGA/EPLD Upgrade Release Notes on Cisco.com Another type of binary file is the software maintenance upgrade (SMU) package file. SMUs contain fixes for specific defects. They are created to respond to immediate issues and do not include new features. SMU package files are available for download from Cisco.com and generally include the ID number of the resolved defect in the filename. For more information on SMUs, see the Performing Software Maintenance Upgrades (SMUs) chapter in Cisco Nexus 3600 System Management Configuration Guide. For information about the supported upgrade paths, see Cisco Nexus 9000 and 3000 Upgrade and ISSU Matrix .

EPLD image

The Cisco Nexus 3636C-R and 36180YC-R NX-OS mode switches contain several programmable logical devices (PLDs) that provide hardware functions in all modules. Cisco provides electronic programmable logic device (EPLD) image upgrades to enhance hardware functions or to resolve known issues. PLDs include electronic programmable logic devices (EPLDs), field programmable gate arrays (FPGAs), and complex programmable logic devices (CPLDs), but they do not include ASICs. In this document, the term EPLD is used for FPGA and CPLDs.

Note

For more information regarding EPLD, refer to Cisco Nexus 3600 Platform FPGA/EPLD Upgrade Release Notes on Cisco.com. Until Cisco NX-OS Release 10.5(2)F, ISSU supports EPLD image upgrades using the install all nxos <nxos-image> epld <epld-image> command during disruptive system (NX-OS) upgrade. While upgrading from pre-10.5(3)F releases to 10.5(3)F and later, you need to upgrade to 10.5(3) NX-OS first using the install all <nxos-image> command. After the NX-OS upgrade is complete, you can upgrade EPLD using the install epld command. Beginning with Cisco NX-OS Release 10.5(3)F, EPLD upgrade takes place during an ISSU system upgrade. If you need to avoid EPLD upgrade, use the skip-epld option. Do not use the epld <epld-image> option as the EPLD image is bundled with the NX-OS images and a separate EPLD image is no longer provided.

Cisco recommends performing a Nexus Health and Configuration Check before performing an upgrade. The benefits include identification of potential issues, susceptible Field Notices and Security Vulnerabilities, missing recommended configurations and so on. For more information about the procedure, see Perform Nexus Health and Configuration Check.

Note	The Cisco Nexus 3600 Series NX-OS Release Notes contain specific upgrade guidelines for each release. See the Release Notes before starting the upgrade.

Before attempting to upgrade to any software image, follow these guidelines:

• Schedule the upgrade when your network is stable and steady.

• Avoid any power interruption, which could corrupt the software image, during the installation procedure.

• On devices with dual supervisor modules, both supervisor modules must have connections on the console ports to maintain connectivity when switchovers occur during a software upgrade. See the Hardware Installation Guide for your specific chassis.

• If you upgrade from a Cisco NX-OS release that supports the CoPP feature to a Cisco NX-OS release that supports the CoPP feature with additional classes for new protocols, you must either run the setup utility using the setup command or use the copp profile command for the new CoPP classes to be available. For more information on these commands, see the "Configuring Control Plane Policing" chapter in the Cisco Nexus 3600 Series NX-OS Security Configuration Guide.

• When you upgrade from an earlier release to a Cisco NX-OS release that supports switch profiles, you have the option to move some of the running-configuration commands to a switch profile. For more information, see the Cisco Nexus 3600 Series NX-OS System Management Configuration Guide.

• By default, the software upgrade process is disruptive.

• Beginning with Cisco NX-OS Release 10.4(2)F, for Nexus 3600-R platform, to upgrade bios to the latest version you should first upgrade to nxos image. This release onwards, the install all nxos command only upgrades the nxos sw to the latest version but the bios image will be upgraded to the last bios released prior to 10.4(2)F version.

  To upgrade to bios released with 10.4(2)F or higher version, first upgrade the nxos image and then use bios-force option to upgrade the bios. For example,

  1. Install all nxos bootflash:nxos64-msll.10.4.2.F.bin.

     The system reloads and boots up with 10.4(2)F image.

  2. Install all nxos bios-force.

     Note	The device reloads twice, once for nxos upgrade and then again for bios upgrade.

• Beginning with Cisco NX-OS Release 10.5(3)F, all NX-OS images are bundled with EPLD image and EPLD upgrade is triggered automatically as part of the install all nxos command. However, you have the option to skip the EPLD image upgrade.

• From Cisco NX-OS Release 10.6(1)F, while installing nx-os using the install all nx-os command on switches affected by secure boot vulnerability, if the IO FPGA version of the device is lower than the Fixed IO FPGA version, EPLD upgrade does not take place. To upgrade the FPGA, use the install epld command. For more information about switches affected by secure boot vulnerability and Fixed IO FPGA version, refer to Table 1 in the FPGA/EPLD Upgrade Procedure to Address Secure Boot Vulnerability document.

• While performing non-disruptive ISSU from Cisco NX-OS Release 10.4(6)M to 10.6(1)F and later releases, on Cisco Nexus 9300-FX switches and line cards, IGMP traffic is forwarded on vPC legs towards the vPC pair. When there are multiple FEX devices on the vPC peer undergoing ISSU, multicast traffic loss can occur during the upgrade of the FEX devices. To resolve this, configure the ip igmp group-timeout 450 command on all VLANs that carry IGMP traffic across the vPC peer link.

Upgrading the Cisco NX-OS software has the following prerequisites:

• Ensure that everyone who has access to the device or the network is not configuring the device or the network during this time. You cannot configure a device during an upgrade. Use the show configuration session summary command to verify that you have no active configuration sessions.

• Save, commit, or discard any active configuration sessions before upgrading or downgrading the Cisco NX-OS software image on your device.

  On a device with dual supervisors, the active supervisor module cannot switch over to the standby supervisor module during the Cisco NX-OS software upgrade if you have an active configuration session.

• Ensure that the device has a route to the remote server. The device and the remote server must be in the same subnetwork if you do not have a router to route traffic between subnets. To verify connectivity to the remote server, use the ping command.

  switch# ping 172.18.217.1 vrf management
  PING 172.18.217.1 (172.18.217.1): 56 data bytes
  64 bytes from 172.18.217.1: icmp_seq=0 ttl=239 time=106.647 ms
  64 bytes from 172.18.217.1: icmp_seq=1 ttl=239 time=76.807 ms
  64 bytes from 172.18.217.1: icmp_seq=2 ttl=239 time=76.593 ms
  64 bytes from 172.18.217.1: icmp_seq=3 ttl=239 time=81.679 ms
  64 bytes from 172.18.217.1: icmp_seq=4 ttl=239 time=76.5 ms
  
  --- 172.18.217.1 ping statistics ---
  5 packets transmitted, 5 packets received, 0.00% packet loss
  round-trip min/avg/max = 76.5/83.645/106.647 ms
  
  

For more information on configuration sessions, see the Cisco Nexus 3000 Series NX-OS System Management Configuration Guide.

Before attempting to downgrade to an earlier software release, follow these guidelines:

• On devices with dual supervisor modules, both supervisor modules must have connections on the console ports to maintain connectivity when switchovers occur during a software downgrade. See the Hardware Installation Guide for your specific chassis.

• Cisco NX-OS automatically installs and enables the guest shell by default. However, if the device is reloaded with a Cisco NX-OS image that does not provide guest shell support, the existing guest shell is automatically removed and a %VMAN-2-INVALID_PACKAGE message is issued. As a best practice, remove the guest shell with the guestshell destroy command before downgrading to an earlier Cisco NX-OS image.

• You must delete the switch profile (if configured) when downgrading from a Cisco NX-OS release that supports switch profiles to a release that does not. For more information, see the Cisco Nexus 3600 Series NX-OS System Management Configuration Guide.

Note	Software downgrades are disruptive. In-service software downgrades (ISSDs), also known as nondisruptive downgrades, are not supported.

Downgrading the Cisco NX-OS software has the following prerequisites:

• Before you downgrade from a Cisco NX-OS release that supports the Control Plane Policing (CoPP) feature to an earlier Cisco NX-OS release that does not support the CoPP feature, you should verify compatibility using the show incompatibility nxos bootflash:filename command. If an incompatibility exists, disable any features that are incompatible with the downgrade image before downgrading the software.