The earliest recollection of this bug is traced back to PAN-OS 11.1.0 - September 02, 2025. This bug is fixed in PAN-OS versions 11.1.6-h17, 11.1.10-h4. Fixed an issue where the MPLS interface eth1/6 went down and remained down, even after replacing the SFP with a supported one and adjusting duplex and speed settings. ( PA-800 series firewalls only ) Upgrading firewalls to PAN-OS 11.0 or later causes SFP ports to go non-operational when the firewall uses forced port mode and the connected peer device operates without auto-negotiation. Workaround: Enable auto-negotiation on the connected peer firewall. For more information: https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-0-known-and-addressed-issues/pan-os-11-1-0-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-1-known-and-addressed-issues/pan-os-11-1-1-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-10-known-and-addressed-issues/pan-os-11-1-10-h4-addressed-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-10-known-and-addressed-issues/pan-os-11-1-10-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-2-known-and-addressed-issues/pan-os-11-1-2-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-3-known-and-addressed-issues/pan-os-11-1-3-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-4-known-and-addressed-issues/pan-os-11-1-4-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-5-known-and-addressed-issues/pan-os-11-1-5-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-6-known-and-addressed-issues/pan-os-11-1-6-h17-addressed-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-6-known-and-addressed-issues/pan-os-11-1-6-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-7-known-and-addressed-issues/pan-os-11-1-7-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-8-known-and-addressed-issues/pan-os-11-1-8-known-issues https://docs.paloaltonetworks.com/pan-os/11-1/pan-os-release-notes/pan-os-11-1-9-known-and-addressed-issues/pan-os-11-1-9-known-issues