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
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”
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
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
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
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
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
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.