This is the previous World Wide Port Name (WWPN) address that was assigned to this vHBA before it changed, recorded here as a history entry. A SAN admin uses this when cleaning up zoning and LUN masking, since a vHBA's storage access is tied to its WWPN and an old WWPN left in zone configs after a change will silently keep an obsolete access path open. For example, after reassigning this vHBA to a new WWPN identity pool, the SAN team checks oldaddr here to find and retire the previous WWPN's zoning entry so it no longer has stale access to the storage array.