Purge Originator Identification for OSPF

In RFC6232(Purge Originator Identification TLV for IS-IS), ISIS POI (Purge Originator Identification) TLV is added to the purge LSP to record the system ID of the IS generating it. At present, OSPF purge does not contain any information identifying the Router that generates the purge. This makes it difficult to locate the source router. While OSPF protocol is difficult to add additional content to the purge LSA, this document proposes generating a POI LSA together with a purge LSA to record the router ID of the router generating the purge. To address this issue, this document defines a POI LSA to record the router ID of the OSPF generating it.