Businesses on heightened alert as war begins.Shortly after the federal government raised its terrorism threat warning to "high" last week and President Bush delivered his ultimatum to Iraqi President Saddam Hussein, Pepco Holdings in Washington, D.C., raised its own security a notch: Visitors into the energy company's headquarters are now severely restricted.At Consolidated Graphics in Houston, the decision was made to block employee access to video downloads as the threat of war transitioned into the beginning of one.The University of Wisconsin in Madison stepped up its vigilance by taking a closer look at traffic passing through its routers and by keeping close tabs on information from monitoring services such as CERT.Across the board, users were taking a second look at security, disaster recovery and other network issues because of concerns about terrorism and increased network traffic. But for the most part companies seem satisfied that security measures already in place - many instituted as a result of Sept. 11 - have them well-protected."Everyone is being extra vigilant," says Doug Cavit, CIO at McAfee Security in Santa Clara. "But ever since Sept. 11 there has been a lot of focus on security. . . . So you can make the argument that in some ways we're in a much better position, and we're kind of reaping the benefits of having done all that prep work."As far as McAfee's own policies go, Cavit says the only real change as a result of the war is a reduction in travel."We are a lot more cognizant of people traveling and where people are. We're being respectful of the fact that people are wanting to stay closer to home," he says.While it's unclear how much of a threat businesses actually face during wartime, analysts say it's a good idea to stay prepared. In February, Gartner launched\u00a0a Weblog\u00a0focusing on the conflict in Iraq and what companies should consider. It discusses everything from business continuity to e-mail policies to how to protect against hackers."Sept. 11 is what we're using as our indicator. . . . Those are the guidelines we're telling people to be prepared for in the event of a serious terrorist attack," says Dan Miklovic, vice president and research director at Gartner. "We see that clients have a renewed emphasis on making sure they're up to date with security, business continuity planning and disaster recovery."Mitch Ray, manager of IT at Consolidated Graphics, says he addressed those issues after Sept. 11, moving the core of his firm's network from its corporate headquarters to its carrier's collocation facility."We wanted to take advantage of their physical security, network security and those kinds of things," Ray says. "I'm not sure what more we could do in that regard to protect ourselves."Ray had concerns about network usage, though, and is using Internet filtering software from 8e6 technologies to block downloads of news feeds. Network utilization climbed above 80% on Tuesday following Bush's speech, and the block was put in place that evening.