The sun has set upon the era of the single-vendor network.
In an effort to save money and expand infrastructure flexibility, networking pros are now building multi-vendor networks– a big departure from the days when they stayed with all-Cisco networks year after year. Enterprises that switch from a single-vendor to multi-vendor network can reduce total cost of ownership (TCO) by 15% to 25% over five years, according to Mark Fabbi, vice president and distinguished analyst at Gartner, who recently penned the research note "
Network engineer Art Foltz recently compared Juniper and Cisco technology while exploring a network refresh at Central Washington Hospital in Wenatchee, Wash. For years, Foltz's network had been 100% Foundry Networks, but he decided to explore multiple vendors for a refresh of both his data center network and his campus LAN. Ultimately he went with Cisco's Nexus line of switches for his data center and Juniper's EX4200 switch for his campus LAN.
"We were negotiating with both vendors and we negotiated very hard with Cisco to meet Juniper's pricing, which they did initially. Then they decided they couldn't. Unfortunately, we had set the budget based on the Juniper pricing. When Cisco couldn't meet it, that finalized our decision,”said Foltz.
Now Foltz is replacing the Foundry switches in his wiring closets with the Juniper EX4200s, while he has ordered two Nexus 7010s, four Nexus 5020s and 30 Nexus 2248 fabric extenders for his data center. "We will be watching the interaction between Cisco and Juniper during a period of testing in December as we bring these two vendors together," he said.
Multi-vendor networks also give enterprises flexibility
Beyond cost efficiency, going with multi-vendor networks can also make it easier for network managers to try new technologies. Often when IT organizations stick with a single incumbent network vendor for too long,network architects find it difficult to deploy new technologies that aren't tied to the incumbent vendor in some way. In a multi-vendor environment, network managers can look at security or voice technology from diverse vendors, for example.
“It's about being able to use best-of-breed,” said Andre Kindness, a senior analyst wih Forrester Research.
The multi-vendor network learning curve
Deploying a multi-vendor environment requires network managers be multi-lingual, which can be a steep learning curve. But Foltz isn’t concerned about additional complexity.
"It's simply a new operating system. We're multilingual already, running a number of different operating systems in our network," he said. "I have a pair of SRX 650s from Juniper internally for firewall separation. We also run Check Point Software [firewalls] at the Internet edge. We're running Meru Networks for wireless. Anyone who is running a network these days is multilingual. There is seldom any vendor that can provide an entire range of equipment. And even those that do have done so through purchasing other companies. None of it is fully integrated.”
Yet the complexity could be more of a challenge for technology and information services supervisor Carl Behmer who is currently running a network powered by both Cisco and HP at Paso Robles Joint Unified School District in California. Behmer is replacing his legacy Cisco network with an HP network. He's completed the transition in all but two school buildings, but his WAN provider is requiring him to keep Cisco routers in each building to peer to the provider's WAN edge routers.
"The Cisco and HP operating systems are supposed to work together and that is true to an 80% to 85% reality. But there are always things that you can't do in HP or that you can't do on Cisco. It's mostly been the Cisco proprietary stuff, like Cisco Discovery Protocol and the VLAN Trunking Protocol. That's been our biggest issue, figuring out trunking and how VLANs are established on HP versus Cisco."
Be careful to keep operations simple in a multi-vendor network
In a multi-vendor network, a well-defined demarcation between vendors simplifies operations, according to Kindness. In fact, he usually advises enterprises who are exploring a multi-vendor network to choose one vendor for the data center and another for the campus network.
"You can't take a dual vendor approach within the data center," Kindness said. "There is so much change with the technology coming along with flattening the network and virtualization. If you look at HP, Cisco, Juniper: all of them have unique technologies to enable that. Outside the data center it's a different story.."
A university client of Gartner was recently planning to introduce Juniper EX4200 switches to wiring closets within an all-Cisco campus LAN, Fabbi said. Originally the client intended to do one-for-one replacements with the Juniper boxes for 10-year-old Catalyst 5500 switches. But this would have been an operational nightmare for the school, explained Fabbi.
"The Catalyst 5500s weren't consolidated in one part of the network or in one building. They were in random places all across the network. If it's randomly mixed like that and you get a trouble call from a person on the third floor in a building, you have to figure out if they are connected to a Juniper or Cisco switch. You're going to play 20 questions before you even get into the CLI [command line interface] and diagnose the problem,” said Fabbi.
Consultants advised the school to maintain simplicity by consolidating part of its infrastructure. The school created 20 or 30 buildings that were all-Cisco, and took some newer Cisco switches out of other buildings to use as replacements for the Catalyst 5500s. Then the school outfitted a few buildings with all Juniper gear in order to minimize the number of interfaces between vendors and simplify operations.
Enterprises must also audit their existing networks and clean out any proprietary and legacy protocols that may conflict with the introduction of a second vendor, Fabbi said.
"We still see fair use of Cisco's old ISL [Inter-Switch Link] protocol between switches," he said. "ISL has been replaced for nearly a decade by well-established standards like 802.1p and 802.1q for VLANs and quality of service, and by 802.1ad for link aggregation. There is no excuse to use some of this old stuff, but some of it has propagated. If you forget about it, you can run into some difficulties. It's one of the reasons why we recommend you do proof-of-concept testing to iron out any issues between vendors."
Foltz tested his Cisco-Juniper multi-vendor network at a Cisco proof-of-concept center, where he examined failover speeds between his Juniper EX4200s and his dual Cisco Nexus 7010s.
Let us know what you think about the story; email: Shamus McGillicuddy , News Editor