You can selectively disable the IPMI version 1.5 sessions at any time. When you disable IPMI version 1.5 sessions, any existing sessions are terminated and future version 1.5 session requests are blocked. If IPMI 1.5 sessions are disabled, IPMItool users must use the IPMI version 2.0 -I lanplus option.
When the IPMI checkbox is enabled, but the v1.5 Sessions checkbox is empty, the IPMI service is operating without supporting v.1.5.