configure cisco lab

Everyone learns a little differently, but the general methods of learning are:

• Visual: Involves the use of the eyes, including diagrams, reading, and printed materials
• Auditory: Involves the use of the ears including lectures, sounds, and related materials
• Kinesthetic: Involves the use of real-time hands-on learning

Everyone can learn using kinesthetic methods, but typically people favor either visual or auditory as a primary learning style. As a result, using either visual or auditory materials with hands-on learning creates a very strong and compelling learning model. This is yet another reason that I place a great emphasis on labs scenarios for technical training.

There are two primary phases to creating a lab for study purposes. The first is design, and the other is the actual physical assembly of the components. In some cases you may be able to create a multiple-use environment from the ground up, but starting with some idea of the goal in mind is a better idea.

Phase I: Design

The purpose of any design process is to create a specific type of outcome, usually related to goals. Knowing what technology and/or certification you want to get practice with can help decide how many resources you might need to assemble. For example, a CCNA-level lab may only require a handful of routers and one switch, where a Cisco Unified Communications Lab may require phones, servers, switches, routers, and so on. For our purposes, let’s just concentrate on a CCENT/CCNA level lab environment.

Creating anything turns out better with a design or blueprint, which is the exact terminology that Cisco uses when outlining their exams. Simplifying the contents of the CCNA (640-802), the requirements include:

• VLAN, Trunks,  and Spanning Tree
• Frame-Relay WAN
• RIPV2, OSPF, and EIGRP Routing
• IPV6
• WLAN (administration only)
• Access-Lists

Fortunately, even many older Cisco routers and switches are capable of supporting the requirements listed above, from IOS version 12.3 and later (my recommendation, 12.4 is far better). Even more to the point, the switching component(s) can involve less expensive Layer 2 platforms and be limited to just one or two. Translating this into specific requirements, the equipment list might look like this:

• 4 Routers (2600 or above, with Trunking Support)
• 1-2 Switches (2900XL, 2950, or newer)
• 1 Frame Relay switch (can be a module in one of the routers)
• 1 ASA-5505 (optional, for access)

There are three generally accepted ways to access equipment for a lab. First, you can rent rack time from a wide number of vendors, which can save on your power bill and simplify practice. Second, for routing platforms, you can use an emulator or simulator, such as Packet Tracer or GNS3. Finally, you can get your own equipment and assemble your own lab, which I think is the best choice. You can utilize spare equipment at work, request some from your local Cisco Users Group, or purchase your own using Craigslist or eBay. Here is a parts list that can make the process straightforward:

4 – Cisco 2620/21 with 1 WIC1-T card
2 – 2912-XL-EN (2924 would be 24 ports)
1 – ASA-5505 (Base License)
NM-4A/S Module for 2600 Series
6 Cat-5 Ethernet Cables
3 DCE to DTE Serial Back to Back Cables

Correctly assembling these components into an easily accessible lab is fairly simple, and I have built enough of them over the years to help simplify the process. One item not listed above that can be helpful is a terminal server, which establishes console-based access to all of the devices in the lab. In the simplest setup, you can simply swap the console cable between each device, but when you have eight or more devices (as I typically do), a terminal server is a big help.

Step 1: Rack, Stack, & Power

While it may not seem like a big deal, the logistics of power and space can actually cause major headaches. To start with, if you operate your lab at home, you will have to foot the power bill, which is one reason I host mine at work when possible. Ideally, a network cabinet or rack is helpful for the physical assembly, and don’t despair if you only need a small one. Creativity is your best friend here; I discovered that an old Exabtyte tape drive cabinet with the “guts” removed was a great improvised substitute. Power can be as simple as a power strip or surge protector, but be very careful not to overload it, or you can create a fire hazard. At this point, run your power cords from the equipment into the strip, and plug everything into it. If it looks sloppy, use cable straps to bundle the cords or fasten them to the rack.

Step 2: LAN Cabling

The second basic step in assembling your certification lab is probably the easiest, namely, cabling the LAN connections. You can use CAT 5/6 cables of any length, but the shorter the better; the exception is adequate length to comfortably reach between devices. Cable all router LAN ports to the switch(es), and if you use multiple switches, cable between the switches with at least two cords.

Step 3: Serial Interface Cabling

The WIC-1T style cards utilize 60-pin connectors similar to older fixed-configuration devices such as the 1600 and 2500 series (see below).

As described in the parts list, you need a specific type of serial cable for back to back connections. Remember that interfaces can operate as DTE or DCE depending on the cable involved. You can purchase DB-60 DTE to DCE cables from a variety of sources (one is www.anthonypanda.com where I personally purchased). If you have spare cables in your work environment, typically DTE, then you can just use or purchase the corresponding DCE cable and connect them together.

Configure

Now for the fun part of the project: configuring it for actual operation. The “real” configuration tasks will be reserved for lab exercises, but some initial setup helps things run more smoothly. The tasks involved are as follows:

Step 1: Frame-Relay Switch Configuration

I have used a variety of different devices over the years for this function, from a Cisco 7010 (huge power-sucking heat generator) to the NM-8A/S module in my current lab environment. The module is a much better approach because it accomplishes the same thing while using existing hardware real estate. The only drawback is that the interfaces are lower speed (128K typically), but in a lab environment that is not problematic.

Remember for the interface naming conventions on Cisco routers, namely slot/port, and with modules the slot is usually going to be 1/X. Assuming use of the module in the parts list, the interfaces are as follows:

• Serial 1/0
• Serial 1/1
• Serial 1/2
• Serial 1/3

Configuration is fairly straightforward. You have to supply frame-relay Data Link Connection Identifiers (DLCI, the Layer 2 addresses in frame-relay) and a few other settings. For the sake of simplicity assume that Router 1 is connected to S1/0, Router 2 is connected to S1/1, and so forth.

The first step is to enable the router to perform frame-relay switching, which is configured in global configuration mode using the frame-relay switching command.  The configuration for the first port would be as follows, with annotations explaining the significance of the commands:

interface Serial 1/0	Physical interface being configured
encapsulation frame-relay	Layer 2 encapsulation type
clock-rate 128000	Port speed (use top speed available)
frame-relay intf-type dce	Designates DCE switch interface
frame-relay route 102 interface serial 1/1 201	Describes the DLCI of frames coming into the interface, and then the destination DLCI and interface
frame-relay route 103 interface serial 1/3 301
frame-relay route 104 interface serial 1/1 401

The concept here is simple: the router on the other end of the cable (DTE side) sends traffic tagged with one of the DLCI values (e.g., 102, 103, 104), then sends it out the interface with a new DLCI number (e.g., 201, 301, 401), and it arrives on the DTE port of the destination router.  This is basically the same logic used by service providers with enormous switches. You can do the same type of thing with ATM or MPLS configured ports, but for ATM you need specific interface types. Following this, you need to configure the rest of the ports to perform the same type of switching tasks.

Step 2: Create Basic Template Configurations

I recommend one final task just to make things easier when you want to erase configurations and start over when you start a new set of lab tasks. Create a set of basic parameters that you will use at the start of most every lab and that will remain constant. Here are the ones that I recommend:

1. Hostname — I prefer to use a single letter which describes the device: R for router, S for switch, F for firewall, etc.. Following that is a numerical value that just describes where the device sits in the topology. Sometimes I include a model number so I know the capabilities of the device. For instance, if the first router in the lab pod is a 2620, I would make the hostname R1-2620.
2. Device access — The device access ports probably will not change substantially, so setting the parameters is a good idea. Usually you only need console or telnet/SSH access but setting the AUX settings for routers is a good idea as well. Basic settings for each are suggested as follows:
   

   line con 0	Console Port
   privilege level  15	Enters privileged mode right away
   password xxxxx	Specifies a password when needed
   No login	Logs you in directly without intervention
   line aux 0	Auxiliary (modem) Port
   password xxxxx	Specifies a password to access the system
   transport input all	Allows any protocol for access (telnet, etc.)
   login	Requires a login process for access
   line vty 0	Virtual Terminal Port (remote access)
   password xxxxx	Specifies a password to access the system
   transport input all	Allows any protocol for access (telnet, etc.)
   login	Requires a login process for access

3. LAN Settings — Most routers that you use in a lab have the capability of supporting VLAN trunking on LAN interfaces. That being the case, set the encapsulation type on the switch(es) to trunking encapsulation right off the bat, and don’t change it.
4. WAN Settings — Serial interfaces on Cisco routers default to HDLC encapsulation, so make certain that you set the ports to frame-relay encapsulation. That way, the interfaces will be up/up when you start off, and you will not have to waste time troubleshooting issues that really are not issues
5. Device Defaults — A few settings are helpful on routers and switches simply so you do not have to deal with ongoing irritating issues. A big help is to disable DNS lookups when you mistype a command, which is the no ip domain-lookup command in global configuration mode. Setting the time zone helps also.

To keep your template configurations readily available, copy them to flash memory using the copy running-config flash: command. When you are done with a lab exercise, you can issue the write erase command and reboot. Once the device completed the boot process, issue the copy flash:<filename> running-configcommand and then reload the configuration.