The　topology　discovery　service　in　Software-Defined　Networking　(SDN)　provides　the　controller　with　a　global　view　of　the　substrate　network　topology,　allowing　for　central　management　of　the　entire　network.　Unfortunately,　emerging　topology　attacks　can　poison　the　network　topology　and　result　in　unforeseeable　disasters.　Although　researchers　have　made　great　efforts　to　mitigate　this　problem,　security　hazards　still　exist.　In　this　paper,　we　propose　Invisible　Assailant　Attack　(IAA),　the　first　combination　topology　attack　capable　of　injecting　and　maintaining　fake　links　even　when　12　existing　defense　strategies　are　deployed　simultaneously.　IAA　consists　of　14　attack　phases　that　apply　multiple　attack　strategies.　Attackers　skillfully　disguise　the　attack　traffic　in　each　phase　so　that　it　looks　like　normal　network　traffic,　and　perform　these　phases　in　a　well-planned　sequence,　thereby　bypassing　existing　defenses　step　by　step.　To　mitigate　this　attack,　we　propose　a　Route　Path　Verification　(RPV)　mechanism　that　orchestrates　multiple　defense　strategies　to　identify　fake　links.　According　to　the　experiments,　RPV　can　successfully　detect　IAA　with　low　overhead:　its　detection　completes　within　1　ms　while　its　per-flow　storage　consumption　is　only　a　few　KB.　©　1993-2012　IEEE.