This is the ID of the LAN Designated Intermediate System on this circuit at this level; if this system is not partaking in the DIS election process, the value returned is the zero-length OCTET STRING. It tells the admin which router currently holds the DIS role on a shared LAN segment, the object to check when diagnosing pseudonode LSP or flooding problems since only the DIS generates the pseudonode LSP representing that segment. For example, this object returning a zero-length string on a circuit the admin expected to have an active DIS indicates that circuit is not even participating in DIS election at that level, worth checking against ciiCircLevel to confirm the level is actually enabled there.