LACP: Minimum links threshold configuration

Support for LACP minimum link is added to the existing minimum-link feature. With minimum-link configuration, the required minimum bandwidth is provided on LAG interfaces. When there are not enough active links to provide the minimum bandwidth, the minimum-link feature brings the LAG interface down. The LACP minimum-link feature enhances the existing minimum-link feature by bringing down the LAG interface on the peer device as well as on the device on which you have configured minimum links. Prior to the LACP minimum-link enhancement, if you configured minimum links on one device but could not or had not configured it on the peer device, traffic would go out on the peer device because the LAG interface on the peer would not be brought down. LACP minimum link is enabled by default when you configure minimum links.