What is Cisco Virtual Stacking and how does it work?
Large, fast networks have to connect powerful switches in order to function properly. It’s the best way to create fast, reliable connections, and the backbone of any significant network is wired, one way or another.
Connecting a bunch of switches comes with its own complications and challenges, and one of the great struggles in network design is configuring the switches so they can operate efficiently across the whole network.
Traditionally, switch stacking is an invaluable tool for this purpose, as it simplifies the network and network management. These days, you can do one better with virtual stacking.
Introduction to Cisco Virtual Stacking
Formally known as StackWise Virtual, Cisco’s virtual stacking software is designed to connect two physical switches so they act like a single logical unit. Cisco emphatically uses loop-free technology to provide faster and more efficient routing.
The virtual stack allows network administrators more freedom in physical placement for their switches without eliminating the easier control and management advantages of stacking switches.
StackWise Virtual is capable of connecting switches at speeds of 10G and higher, making it viable for high-end applications such as data centers.
How It Works
To utilize StackWise Virtual, the two switches still need a physical connection — typically a high-speed Ethernet cable. Once connected, a master switch is selected and is able to manage the other switch, but the software is a little more sophisticated.
Through the spanning tree, StackWise Virtual will link the connected switches so that they are a single node instead of two. All of the advantages of virtual stacking stem from this design element. Because the switches are treated as a single unit, routing, managing the switches, and many other factors of networking work cleaner and more efficiently.
Benefits of Virtual Stacking
In fact, StackWise Virtual offers a range of benefits over other configurations, including a number of physical stacking connections. Let’s explore these benefits to get a better idea of what virtual stacking really has to offer your networks.
No Loops
Even though one switch is designated as a master in a conventional sense, StackWise Virtual creates loop-free topologies. The subordinate switch does not have to send traffic back through the master switch for routing.
This prevents redundant traffic flows that are common in other stacking architectures. The results are faster networking, cleaner routing, fewer bottlenecks, and superior performance across the board.
SSO Redundancy
StackWise Virtual provides SSO supervisor redundancy. Single sign-on networking is valuable for fast internet traffic management and end-user quality of life, but it can create network stalls and bottlenecks.
With single sign-on, the supervisor is often a bottleneck where traffic has to wait for authorization. By creating a redundant supervisor, StackWise Virtual reduces this problem.
The mechanism is simple. There is a primary supervisor and a backup supervisor. If the primary supervisor is backlogged or stalled, the backup fires up and checks credentials to approve traffic. This happens in Layer 2, keeping traffic flows fast and uninterrupted.
Cleaner Configuration
Virtual stacking can improve configurations in general — especially when no-loop topologies are exploited. StackWise Virtual adds more features that help with configuration and efficiency.
One feature is the elimination of FHRP (first hop redundancy protocols) like VRRP, GLBP, and HSRP. These redundancy protocols introduce delays into the system and complicate network configuration.
StackWise Virtual can eliminate the need for FHRP without creating risks or errors. The end result is a configuration with fewer errors and better performance.
Return on Investment
Most importantly, StackWise Virtual is good for your bottom line. With freedom in virtual stacking, you can squeeze more bandwidth out of the access layer of your network, increasing the network’s value from the start.
At the same time, virtual stacking is simple, reliable, and scalable, hitting all of the key notes for high-value networking investment. StackWise virtual can lower labor costs by making network design and management easier and less labor-intensive. Because it is reliable, you will spend less time and money on troubleshooting and fixing network problems.
It’s also scalable. You can virtually stack new hardware one switch at a time if necessary, or you can upgrade in bulk. With that flexibility, it’s much easier for your network to keep up with its own growth without creating significant service disruptions along the way.
Virtual stacking can and will save you money if you take advantage of these benefits.
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