The traditional OSPF recovery is based on calculating new shortest paths from a node to {HEAD ~ all the destinations} in {TAIL ~ the changed topology} 
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The traditional OSPF recovery is based on calculating new shortest paths from a node to { HEAD ~ all the destinations } in { TAIL ~ the changed topology }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL