A TechRepublic member recently posted a comment to one of my articles, asking a common question I've heard from many network administrators. Jpr75 wanted to know how one could best select a Cisco device according to networking and organizational needs.
When it comes to choosing a Cisco device, you have several options to help you make the decision. Let's take a look some of the ways you can find the Cisco router that best meets your company's requirements. (While we'll focus on selecting routers, the process for selecting switches is very similar.)
Go with what you know
When I think of Cisco routers, I usually think of Cisco's 2600 and 3600 series lines. For many years, these lines served as the standard Cisco routers for a midsize business' network. In fact, most organizations still use these models today—even though Cisco discontinued both lines more than a year ago.
But despite that fact, if I had a new site to add to my 70-location WAN, I would still select a Cisco 3640 router. I can purchase a used one for less than $2,000, it offers everything I need, and I've installed the same router at every other remote location.
That's one way to select a product for an existing network—going with what you know. Notice that I didn't even need to really consider what the router offers—after 70 locations, product selection has become almost a "cookie-cutter" process.
Of course, this approach does have its drawbacks. For example, choosing a discontinued product means you don't exactly get a lot of the new Cisco features.
Do your homework
However, if you're selecting a router for a new network or function, you can't necessarily rely on the same old router. How do you know which router to select? In my experience, evaluating and weighing the following eight criteria can help you figure out which router best fits your needs.
Cisco used to rate its routers by how many packets per second the router could forward. For example, a Cisco 2610 or 2612 series router can forward an estimated 15,000 packets per second using fast-switching; a Cisco 7500 series router can forward an estimated 2 million packets per second.
However, this type of information isn't as readily available as it once was. That could be because the metrics are only estimates under optimal conditions. When you start adding any features, such as QoS, firewalls, or VoIP, all the numbers change.
Router processors are rarely upgradeable, so this refers primarily to RAM and Flash.
This refers to the number of WAN and LAN interfaces supported by the router. The router usually has a default number of interfaces—but some routers, such as the 3600 series, have none. So, pay attention to the number of interfaces you can add on top of the default.
For example, you might need a router to support a certain interface or a VoIP feature.
services" supported by the router
This refers to functionality supported by a router that previously required separate boxes. For example, a 16- or 32-port switching module in a router negates the need for an Ethernet switch; having a firewall, VPN server, and IDS/IPS sensor in a router can negate the need for a firewall, VPN concentrator, and dedicated IDS/IPS appliance.
How easy or difficult is it to manage the router? Does the router come with a GUI interface, or is it command line only? Is there an interface that allows you to manage multiple routers to help ease the management burden as the enterprise grows?
Does the router offer the necessary redundancy for working at a critical point in the network? Some redundancy examples include hot-swappable power supplies or high-availability routing protocols such as HSRP or VRRP.
Cisco routers are traditionally very reliable, and Cisco traditionally offers a high level of support. When purchasing a router, you will have various levels of support options. Select the best level for your organization.
Of course, using these features in your decision-making process requires some research. You could peruse the Cisco Routers Product Portfolio, scan through the specifications, and select the router yourself.
Or, you could also use the criteria above to work with a reseller or directly with Cisco to determine which routers offer the features you need. Cisco offers a well-written, in-depth Router Guide (a PDF file) that compares all of its current routers. Either way, you must ask plenty of questions, do your research, and be able to justify the decision you make.
Rely on the experts
But these aren't your only options when it comes to choosing a Cisco router. In fact, you can take advantage of the Cisco Product Advisor, which can make the router selection for you. Plus, you don't need to be a registered Cisco user to access this tool.
The Cisco Product Advisor is a neat, time-saving tool to assist in selecting the right Cisco device for your network needs. It asks you questions and suggests an appropriate product based on your answers. This tool has four categories: Routers, Switches, Firewall Appliances, and Wireless Products.
Let's walk through using this tool. From the Cisco Product Advisor Web page, select which type of hardware you're looking for: routers, switches, firewalls, or wireless products. For this example, choose Routers. The tool will then ask whether you're a novice, expert, or just looking for a feature-by-feature comparison. Make your selection, and click Next.
Again, for this example, choose Expert in order to view all of the different features you can use to select a Cisco router. Click the Figure A thumbnail to see a screenshot of the list of available features.
For this example, I chose Corporate Office/Central Site from the Environment section, Redundant Power Supply from the Redundancy Options section, Gigabit Ethernet from the LAN Connectivity section, and 11-30 from the Max. WAN Port Density (All 'WAN Connectivity' Types) section. From my selections, the Product Advisor returned eight routers that fit my requirements. Click the Figure B thumbnail to see a screenshot of the results.
Next, you can choose up to three products to compare. Make your selections, and click Compare. For this example, I chose to see a side-by-side comparison of the 2811 and 2821 routers. The Product Advisor then provides a long list of features that each router offers. Click the Figure C thumbnail to see a screenshot of this comparison.
From the results, I can see that the 2821 offers one more DSP, features an EVM-HD, has a maximum of 1GB of DRAM, and includes two rack units. Other than these "extras," the two routers are very similar—not surprising, considering that their part numbers are similar.
Once you've compared the features and made a decision, you can order the router from Cisco or a Cisco Partner. Or, you can take this information to a reseller to purchase the device.
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David Davis has worked in the IT industry for 12 years and holds several certifications, including CCIE, MCSE+I, CISSP, CCNA, CCDA, and CCNP. He currently manages a group of systems/network administrators for a privately owned retail company and performs networking/systems consulting on a part-time basis.