HP has had a dismal record for big acquisitions, having written off multibillion-dollar acquisitions of Autonomy and technology outsourcing provider EDS, which it bought in 2008.
The purchase of Aruba would help HP boost its share in the wireless local area network (WLAN) market as more companies allow employees to access work systems through their wireless devices.
"I think it will add a layer of high-growth revenue to the mix in a way it helps HP reach its goal of growing faster," Atlantic Equities analyst Josep Bori told Reuters.
HP is way behind market leader Cisco Systems Inc in the networking business, and the Aruba acquisition would help it to gain a little more market share, he said.
HP has a 4-5 percent share of the enterprise WLAN market, compared with Aruba's 10-13 percent, FBN Capital Markets analyst Shebly Seyrafi estimated in a note dated Feb. 27.
The WLAN market is estimated to grow 40 percent to about $13 billion in 2019, according to market research firm Dell'Oro Group.
HP, which has struggled to adapt to mobile and online computing, plans to separate its computer and printer businesses from its corporate hardware and services operations this year.
Aruba sells Wi-Fi gear to a wide range of clients including California State University and Dalian Wanda Group, which controls China's biggest property developer and largest cinema chain.
The purchase will also help HP better compete for E-Rate - the largest U.S. educational technology subsidy program - which helps connect schools and public libraries to high-speed Internet, JMP Securities analyst Erik Suppiger said.
In December, the Federal Communications Commission voted to raise funding for the E-Rate program by $1.5 billion to $3.9 billion.
The all-cash offer of $24.67 per share is a premium of 34.4 percent to Aruba's close on Feb. 24, the day before Bloomberg reported about a possible deal.
Aruba shares fell 1.6 percent to $24.41 in afternoon trading on Monday. The stock had risen about 40 percent since the Bloomberg report. HP shares were down marginally at $34.76.
HP's cash pile stood at $12.9 billion at the end of January.
Evercore Partners and Catalyst Partners served as financial advisers to Aruba.
© Thomson Reuters 2015