A few security software names are getting a lift from the Cisco/Sourcefire deal, as investors bet the deal will spur further M&A activity (whether from Cisco or another IT giant). PFPT +5.5%. IMPV +3.6%. QLYS +1.8%. Fortinet is still up strongly (previous), but Palo Alto Networks (PANW +0.7%) has given up nearly all its gains, as M&A enthusiasm is tempered by concerns Sourcefire and its advanced intrusion-analysis tech will better position Cisco to compete against Palo Alto's next-gen firewalls and related security services.Of course, tying together disparate pieces of hardware and software into an integrated security platform can be easier said than done.