rtg Dpn Mid Substitute Rid

This attribute indicates the substitute RID in use for the MID. This RID will be substituted for the RID in DPN packets destined to the local node's RID and the MID in question when the MID is unreachable (when, for example, all links to an AM from the Passport subnet are down). It will also be used in the case where the path through the substitute RID is better than that available through the subnet's connection to the cluster containing the AM MID. Substitute RIDs are learned from AM clusters that are supported by two RIDs (the Passport subnet's RID and another one). The operator can check this value to determine if a possible back up route to an AM exists. When there are no delayNextHopLinkGroups or tputNextHopLinkGroups shown to reach the MID, the substitute RID will be used. A value of 128 indicates that no substitute RID is known.