Cisco's market share in the fast-growing 10GbE market segment stands at 66.8 percent in the second quarter. No other vendor even comes close to Cisco. The closest is Hewlett-Packard with a 9.2 percent share.

The Ethernet switch market is still growing -- and Cisco is still dominating. IDC's latest report shows Ethernet switch revenues reached $5.5 billion in the second quarter, an 8.5 percent increase year-over-year. Rohit Mehra, director of Enterprise Communications Infrastructure at IDC, said the positive second-quarter performance in the Ethernet switch market, which builds on momentum from the previous quarter, shows that the network continues to play a pivotal role in IT infrastructure rollouts.

"10GbE along with the emerging 40GbE Ethernet switch segments are leading the market to higher levels, clearly proving the point that growth in applications, virtualization, and mobility have to be looked at in conjunction with the underlying wired infrastructure in data centers and campus deployments," Mehra said.

Cisco's 60-Plus Percent

Breaking down the Ethernet switch market, 10GbE switch revenue increased 22.9 percent year-over-year. 10GbE port shipments grew to a record 3 million ports in the quarter and continue to drive the overall market growth. The layer 4-7 switching market grew 11.2 percent year-over-year to reach $376.1 million.

"Even the Gigabit Ethernet segment showed strength in 2Q12 with over 55 million ports shipped in the quarter, and market revenues growing 6.5 percent from the previous quarter," said Petr Jirovsk�, senior research analyst in IDC's Networking Trackers Group. "The overall market drivers, such as proliferation of video traffic on the network, are mitigating to a large extent the increased macroeconomic uncertainty and weakness in the public sector in many regions."

Cisco's Ethernet switch market share in the second quarter came in at 62.1 percent, reflecting a small year-over-year decrease from 62.6 percent. Cisco's market share in the fast growing 10GbE market segment stands at 66.8 percent in the second quarter.

No other vendor even comes close to Cisco. The closest vendor in the running is Hewlett-Packard with a 9.2 percent market share. Alcatel-Lucent has about 3 percent of the market share, while Huawei and Juniper hold 2.85 percent and 2.48 percent, respectively.

Threats to Cisco

We caught up with Zeus Kerravala, principal analyst at ZK Research, to get his take on Cisco's market dominance -- and if anything can threaten its reign in the Ethernet switch realm. Kerravala is a firm believer that significant market share shifts occur only during market transitions.

"Cisco has kept in front of market transitions. Cisco has followed trends like embedded security and Wi-Fi very closely. So they managed to maintain their lead as far as market transitions go," Kerravala told us.

"The big threats to Cisco on the Ethernet side would be all the activity going on in the data center, with software -defined networks as well as on the access edge with more growth over Wi-Fi. That could upset the Ethernet apple cart for Cisco. There's potential there, but I don't expect them to have any real significant share loss."