User story: As a system administrator, I need NM-libreswan to process leftsubnet configurations, to establish secure net2net IPsec tunnels between specified subnets. Acceptance criteria: Given a system administrator configuring IPsec connection that includes leftsubnet and rightsubnet specifications, When they configures these parameters in NM-libreswan, Then NM-libreswan should configure the IPsec tunnel to encrypt traffic between these subnets, ensuring that the XFRM policies reflect the specified subnet configurations. Definition of Done: The implementation meets the acceptance criteria Unit test and integration test are written and pass The code is part of a downstream build attached to an errata The Release Note text is written following the feature-reason-result format. The fix needs to be backported into RHEL-9.2 AC and Demo/QE test alignement: The demo showing configuration of IPSec tunnel configured with leftsubnet and rightsubnet can be found here: https://drive.google.com/file/d/1ZjdiYMvwYEyPEVo_hB1RUi8_zqVDCs4m/view

.NetworkManager now supports the `leftsubnet` parameter for IPsec VPNs With this update, NetworkManager supports the `leftsubnet` parameter to define the private subnet behind the local participant used to configure subnet-to-subnet scenarios in Internet Protocol Security (IPsec) VPNs.