Cisco Systems Inc. (Nasdaq: CSCO) haslost one of its top routing experts, Dr. Yakov Rekhter, to arch-rival Juniper Networks Inc. (Nasdaq: JNPR).

“This is a significant blow to Cisco, on two fronts,” says David Newman,president of Network Test. “First, Rekhter is by any measure a heavyweightin terms of network protocol design. Second, there's a seriousperception/marketing issue for Cisco. Juniper's been steadily eroding marketshare in core Internet devices for a while. Nowthey've got the guy who's been widely perceived as one of Cisco's top rocketscientists. It's a huge loss for Cisco.”

Rekhter co-wrote BGP (border gateway protocol) version 4, the protocol that makes the global Internetpossible. He also co-wrote key pieces of MPLS (multiprotocol label switching), the protocol some tout as thebest hope for scaling IP QOS and security. He's co-author of the leadingtext on MPLS. And if that isn’t enough, he also co-wrote the "privateaddressing" RFC that Newman credits for keeping the Internet from running out ofIP addresses “for the past 10 years.”

Industry observers think that other defections could follow. “In general,Cisco is now a much easier place to recruit from, since many there believethe ride is over,” says a partner at a venture capital firm in SiliconValley, who requested anonymity.

Juniper’s wooing of Rekhter represents a second victory in the last two weeks inits battle against Cisco. A recent report credited Juniperwith increasing its share of the core routing market from 22 to 29 percent(see Juniper Eats Into Cisco's Lunch).

Still, it hasn’t all been doom and gloom for Cisco on the recruitingfront. In November it lured its original CTO, Ed Kozel, back into the fold(see Ed Kozel Is Back at Cisco).

And a former colleague of Rekhter’s downplays the impact of hisdefection. “Rekhter is one of the minor deities in routing, but his departurewon't have much impact on Cisco,” he says. "Rekhter spent most of his time onstrategic issues and didn't really have much to do with product development.”

He suspects that Rekhter is leaving Cisco for the same reasons that he leftIBM Corp. (NYSE: IBM). "He doesn't like working for big corporations, and he doesn't likeworking for startups," he says, noting that Juniper is now about the sizethat Cisco was when Rekhter joined it.

Juniper confirmed that it had hired Rekhter but declined further comment. Cisco did not return calls.

Cisco closed down $4.94 (12.91%) at $33.31. Juniper closed down $23.50(18.64%) at $102.56.

-- Stephen Saunders, US Editor, Light Reading http://www.lightreading.com