188.8.131.52 Unregistering a Peer Name
Create a Revoke CPA for the Peer Name. This CPA MUST have the R field set to indicate that this is a revoke CPA.
The Revoke CPA MUST be sent via a FLOOD message with the D flag clear to the two nodes in the Leaf Set with PNRP IDs that are closest to the locally registered PNRP ID. That is, the numerically closest PNRP ID that is greater than the local PNRP ID and the numerically closest PNRP ID that is less than the PNRP ID MUST be used.
The node MUST select the node that has the PNRP ID immediately greater than the Local PNRP ID. The node MUST send the PNRP ID via a FLOOD message (with the D flag clear) to the node with a PNRP ID that is the fifth closest and smaller than the local PNRP ID. The process is also reversed. The node MUST select the PNRP ID that is immediately less than the local PNRP ID. This entry will be sent via a FLOOD message (with the D flag clear) to the fifth closest and larger PNRP ID that the node knows about.
In this manner, the Leaf Sets of the nodes at the edge of this node's Leaf Set will know fully about the existing neighbors.
If there are no longer any locally registered PNRP IDs, stop publishing the address used by the node in SSDP (as specified in [UPNPARCH1], section 1).
Whenever a FLOOD message with the D flag clear is sent, the node MUST also put the FLOOD message in the Pending List, set its Retry Count to 2, and start its Message Retransmission Timer.