After the shutdown command is executed on an interface of an S series switch, an LSA sent by the switch still exists in the peer LSDB. Why

Question: Two devices are connected using a link. After the shutdown command is executed on an interface on one end of the link, an LSA sent by the interface still exists in the peer LSDB. Why?
Answer: An LSA can be flooded only by the S series switch supporting OSPF that generates the LSA. When the peer switch has no reachable path to the local switch, new LSAs generated by the local switch will not be flooded to the peer. Therefore, the old LSA exists in the peer LSDB. It is not used in SPF calculation and ages with time.

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