The first group will "get it" and welcome not having to troubleshoot routers in the middle of the night. They would rather work with other IT and business managers to address broader enterprise issues, Skorupa said. The second group won't be ready at first but will advance their skills and eventually find a place in the new landscape.
The third group will never get it, Skorupa said. They'll face the same fate as telecommunications administrators who relied for their jobs on knowing obscure commands on TDM (time-division multiplexing) phone systems, he said. Those engineers got cut out when circuit-switched voice shifted over to VoIP (voice over Internet Protocol) and went onto the LAN.
"All of that knowledge that you had amassed over decades of employment got written to zero," Skorupa said. For IP network engineers who resist change, there will be a cruel irony: "SDN will do to them what they did to the guys who managed the old TDM voice systems."
But SDN won't spell job losses, at least not for those CLI jockeys who are willing to broaden their horizons, said analyst Zeus Kerravala of ZK Research.
"The role of the network engineer, I don't think, has ever been more important," Kerravala said. "Cloud computing and mobile computing are network-centric compute models."
Data centers may require just as many people, but with virtualization, the sharply defined roles of network, server and storage engineer are blurring, he said. Each will have to understand the increasingly interdependent parts.
The first step in keeping ahead of the curve, observers say, may be to learn programming.
"The people who used to use CLI will have to learn scripting and maybe higher-level languages to program the network, or at least to optimize the network," said Pascale Vicat-Blanc, founder and CEO of application-defined networking startup Lyatiss, during the Structure panel.
Microsoft's Gill suggested network engineers learn languages such as Python, C# and PowerShell.
For Facebook, which takes a more hands-on approach to its infrastructure than do most enterprises, that future is now.
"If you look at the Facebook network engineering team, pretty much everybody's writing code as well," said Najam Ahmad, Facebook's director of technical operations for infrastructure.
Network engineers historically have used CLIs because that's all they were given, Ahmad said. "I think we're underestimating their ability. "
Cisco is now gearing up to help its certified workforce meet the newly emerging requirements, said Tejas Vashi, director of product management for Learning@Cisco, which oversees education, testing and certification of Cisco engineers.
With software automation, the CLI won't go away, but many network functions will be carried out through applications rather than manual configuration, Vashi said. As a result, network designers, network engineers and support engineers all will see their jobs change, and there will be a new role added to the mix, he said.
In the new world, network designers will determine network requirements and how to fulfill them, then use that knowledge to define the specifications for network applications. Writing those applications will fall to a new type of network staffer, which Learning@Cisco calls the software automation developer. These developers will have background knowledge about networking along with skills in common programming languages such as Java, Python, and C, said product manager Antonella Como. After the software is written, network engineers and support engineers will install and troubleshoot it.
"All these people need to somewhat evolve their skills," Vashi said. Cisco plans to introduce a new certification involving software automation, but it hasn't announced when.
Despite the changes brewing in networks and jobs, the larger lessons of all those years typing in commands will still pay off for those who can evolve beyond the CLI, Vashi and others said.
"You've got to understand the fundamentals," Vashi said. "If you don't know how the network infrastructure works, you could have all the background in software automation, and you don't know what you're doing on the network side."