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Table of Contents Expand all

play_arrow Overview
- AI-ML Data Center Overview
play_arrow Upgrade
- Recommended Release
- Unified ISSU for AI-ML Data Centers
play_arrow Load Balancing
play_arrow Traffic Management
play_arrow BGP
play_arrow EVPN-VXLAN
- EVPN-VXLAN for AI-ML Data Centers
- IPv6 Underlay for an IPv4 EVPN-VXLAN Fabric
play_arrow Authentication
- 802.1X Authentication on Layer 2 Interfaces

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English

Unified ISSU for AI-ML Data Centers

date_range 27-Feb-25

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Use unified in-service software upgrade (ISSU) to minimize traffic loss during the software upgrade process.

Overview

In an AI-ML data center deployment, the large data flows, also known as elephant flows, traveling through the network mean that even a low percentage of lost traffic can be a large number of packets. As the network administrator, you can use the unified in-service software upgrade (unified ISSU) feature to upgrade to a more recent release of Junos OS Evolved with no disruption on the control plane and minimal loss of traffic.

Benefits

Eliminates network downtime during software image upgrades.
Reduces operating costs while delivering higher service levels.
Enables you to implement new features more quickly.

Configuration Overview

When you are planning to perform a unified ISSU, choose a time when your network is as stable as possible. As with a normal upgrade, Telnet sessions, SNMP, and CLI access are briefly interrupted.

We recommend that you read the Unified ISSU for Junos OS Evolved topic to anticipate any special circumstances that might affect your upgrade.

For AI-ML data center deployments, the following configurations do not roll over to the upgraded operating system with unified ISSU. You must reconfigure these features after the upgrade is complete:

Generic routing encapsulation (GRE) tunnels
sFlow
Port mirroring
Multicast Internet Group Management Protocol (IGMP) snooping and Protocol Independent Multicast (PIM)
Virtual Router Redundancy Protocol (VRRP)
Link Aggregation Control Protocol (LACP)
Bidirectional Forwarding Detection (BFD) protocol

Prepare to Run the Upgrade

Make sure that you have sufficient disk space for the upgrade and that a backup of the system is available. Save the system configuration and the information about how the system is handling traffic.
You can do this by following the procedure at Before You Upgrade or Reinstall Junos OS Evolved.

You will need the information about the system configuration and how the system is handling traffic when you verify that the upgrade was performed correctly.
Download the software package from the Juniper Networks Support website at https://www.juniper.net/support/ and place the package on your local server.
If the BGP protocol is configured on the main routing instance or a specific routing instance, then configure BGP graceful restart. Set the restart time value to greater than or equal to 300 seconds.
Note:
Changing the restart-time for BGP graceful restart causes the existing BGP sessions to restart, which might cause disruptions. We recommend that you perform this action during a low network usage time to avoid traffic loss.

Configure the following on the device you are upgrading as well as its BGP peers.

To configure BGP graceful restart and the restart-time value on the main routing instance, issue the following commands:
```
[edit]
user@host# set routing-options graceful-restart
[edit]
user@host# set protocols bgp graceful-restart restart-time 300
```
To configure BGP graceful restart and the restart-time value on a specific routing instance, issue the following commands:
```
[edit]
user@host# set routing-instances routing-instance routing-options graceful-restart
[edit]
user@host# set routing-instances routing-instance protocols bgp graceful-restart restart-time 300
```
If a Spanning Tree Protocol (STP) is configured, then configure the STP-enabled ports as edge ports and enable bridge protocol data unit (BPDU) protection.
Depending on the type of STP configured, issue the following commands:
```
[edit] 
user@host# set protocols (mstp | rstp | vstp) bpdu-block-on-edge
[edit]
user@host# set protocols (mstp | rstp | vstp) interface (interface-name | all) edge
```
Configure the value of the Address Resolution Protocol (ARP) aging timer to the maximum value of 240 minutes. Extending the aging timer to its maximum value gives the device time to upgrade between ARP updates.
```
[edit]
user@host# set system arp aging-timer 240
```
On the BGP peers of the device you are upgrading, set the number of ARP retry attempts to 300. If the number of retries is too low, the peer device might stop trying to reconnect before the upgrade is complete.
```
[edit]
user@peer-device# set system arp arp-retries 300
```
Copy the software image to the /var/tmp/ directory of the device running Junos OS Evolved using the scp command.
For example:
```
user@host> file copy scp://junos-evo-install-qfx-ms-x86-64-22.1R1-S1.2-EVO.iso /var/tmp/junos-evo-install-qfx-ms-x86-64-22.1R1-S1.2-EVO.iso
```
Validate the existing configuration against the new software image to check whether it supports unified ISSU by using the request system software validate-restart package-name command.
For example:
```
user@host> request system software validate-restart /var/tmp/junos-evo-install-qfx-ms-x86-64-22.1R1-S1.2-EVO.iso 
```

Run the Upgrade

After you have completed the tasks above, run the request system software add package-name restart command on the device that you want to upgrade.

For example:

content_copy zoom_out_map
user@host> request system software add /var/tmp/junos-evo-install-qfx-ms-x86-64-22.1R1-S1.2-EVO.iso restart 

The system restarts or reboots to load the new software image. When the upgrade is complete, the device displays the login prompt.

Verify the Upgrade Was Successful

At the login prompt, log in and verify the release of the installed software, using the show system software list command.
Verify that the system is running properly and correctly handling traffic by repeating the steps in the procedure in Before You Upgrade or Reinstall Junos OS Evolved. Compare the information about the system configuration to what you collected before you installed the software package.
If you need to make any changes to the configuration after the upgrade, remember to back up the software and configuration using the request system snapshot command. See Back up and Recover Software with Snapshots.
If the unified ISSU fails for some reason, and if the CLI is still working, you can follow the steps in Recover from a Failed Installation Attempt If the CLI Is Working to install the software image.
Reconfigure any applicable features listed in the Configuration Overview above. Commit your changes.

Platform Support

See Feature Explorer for platform and release support.

AI-ML Data Center Feature Guide

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