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PR1552955 - PTX MAC Addresses changed after upgrade to Junos Evolved version 21.1R1-EVO or later



Article ID: TSB18219 TECHNICAL_BULLETINS Last Updated: 21 Dec 2021Version: 5.0
Alert Type:
SRN - Software Release Notification
Product Affected:
PTX running Junos Evolved Software
Alert Description:
When upgrading Junos Evolved software to versions with the change via PR1552955, the Ethernet MAC addresses on the interfaces will be changed. If your deployment depends on static MAC address configurations, you should make a plan to accommodate this.
Risk Risk Description
Low/Notification - No defined time impact to take action Upgrading to Junos Evolved version 21.1R1 or later will see this immediately
Impact Impact Description
Low/Notification - Monitor the situation but no action needed Installations depending on static MAC addresses need to modify to deal with this change.


Ethernet MAC addresses on a router running Junos Evolved software are assigned using a base Ethernet address and the port number.

Before this change, i.e. a node running 20.4Rx-EVO or earlier, the software miscalculated the number of required MAC addresses per physical port. We implement the change in our software to correct this.

After upgrading software, i.e. a node running 21.1R1-EVO or later, the Ethernet MAC addresses starting from port et-0/1/0 may change from the pre-upgrade values. There is no change for port et-0/0/x.

This notification applies to Junos Evolved software version 21.1R1-EVO or later
Modification History:
2021-12-15 First publication

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