In VyOS 1.3, this command was used to integrate with StrongSwan's uniqueids=no setting in ipsec.conf, facilitating environments requiring non-unique IKE_SAs. However, with StrongSwan's transition to swanctl.conf, such unique ID management should ideally be performed via the connections.<conn>.unique parameter. More details about the migration you can find here.

Additionally, the current set vpn ipsec remote-access connection rw unique command in newer VyOS versions supports modern uniqueness policies, which align better with updated StrongSwan configurations. https://vyos.dev/T1210

Given the situation, I can propose the following actions:

1. Deprecate disable-uniqreqids: Phase out this command and guide users to the remote-access uniqueness settings.
2. Modernize Configurations: Transition settings to use the connections.<conn>.unique parameter, defaulting to similar behavior as uniqueids=no.
3. Standardize Behavior: Apply the same uniqueness handling as the remote-access settings (L2TP, profile, peer) for consistency across the platform.

Other helpful links:

• https://docs.strongswan.org/docs/latest/swanctl/swanctlConf.html#_connections_conn_unique
• https://wiki.strongswan.org/projects/strongswan/wiki/ConfigSetupSection
• https://vyos.dev/T2647

I think we should go for option #2, since it's pretty flexible now. The old disable-uniqreqids option can be migrated to never on every connection.