Cisco Training Lab Network

I set up a Cisco equipment training lab for myself today using some spare Cisco equipment.  The diagram below outlines the basics of the network that I set up.  You can use this information as a guide for how to set up a basic Cisco training lab!  I'll be doing some more interesting stuff with this setup as time goes on.

TOP is a Cisco 3640 with a few WIC 1DSU T1 controller cards installed.

BOTTOM is a Cisco 3825 router with a few VWIC2-2MFT-T1/E1 controller cards installed.

SMALL is a Cisco 1841 router with one VWIC2-2MFT-T1/E1 controller card installed.

SWITCH is a Cisco Catalyst 2950; a 24 port fast Ethernet switch.

In order to connect the routers back-to-back without an ISP between them, just create some cables that switch wires 1 & 2 with 4 & 5 on one end (normal straight cable on the other end).  If you're comfortable creating straight-through cat5/cat6 cables, just create a cable with OW-O-GW-Bl-BlW-G-BrW-Br on one end and Bl-BlW-GW-OW-O-G-BrW-Br on the other end.  The reason behind this cable wiring is that both routers will be sending on wires 4 & 5 and listening on wires 1 & 2.  Therefore, you must swap these two pairs so that when router 1 sends on 4 & 5, the signal will end up on router 2's listening wires, 1 & 2.

Depending on the router, you may have to set up the controller module before a serial interface even appears:

BOTTOM>enable

BOTTOM#configure terminal

BOTTOM(config)#card type t1 0 0

----- This tells the router that you have a T1 card in slot 0/0. The card's amber light(s) will probably come on now.

BOTTOM(config)#controller t1 0/0/0

BOTTOM(config-controller)#framing esf

BOTTOM(config-controller)#linecode b8zs

BOTTOM(config-controller)#clock source internal

BOTTOM(config-controller)#channel-group 0 timeslots 1-24 speed 64

----- The command above will cause the router to create a serial interface.

BOTTOM(config-controller)#interface s0/0/0:0

BOTTOM(config-if)#encapsulation ppp

BOTTOM(config-if)#ip address 192.168.1.1 255.255.255.252

BOTTOM(config-if)#no shutdown

----- The mask of 255.255.255.252 (192.168.1.1/30) breaks the 192.168.1.0/24 (255.255.255.0) subnet into many smaller subnets with 2 usable IPs each - perfect for point-to-point links!  The 192.168.1.0/30 subnet consists of the following IPs:

-- 192.168.1.0 (network IP)

-- 192.168.1.1 (usable IP - BOTTOM router)

-- 192.168.1.2 (usable IP - TOP router)

-- 192.168.1.3 (broadcast IP)

If you're not comfortable with subnetting information like this, read up on it!  It's very important knowledge for anyone working on routers and switches.

The commands listed above are all that are required (and some are optional) on this router to set up a basic point-to-point interface.  Now, we need to set up the interface on one of our other routers, TOP, which requires a slightly different method because of the different interface card used:

TOP>enable

TOP#configure terminal

TOP(config)#interface s0/0

TOP(config-if)#service-module t1 clock source internal

TOP(config-if)#service-module t1 framing esf

TOP(config-if)#service-module t1 linecode b8zs

TOP(config-if)#service-module t1 timeslots 1-24 speed 64

----- The last 4 commands replace the card and controller configuration commands used on BOTTOM, the last router we configured.

TOP(config-if)#encapsulation ppp

TOP(config-if)#ip address 192.168.1.2 255.255.255.252

TOP(config-if)#no shutdown

We should now have a working, usable point-to-point link between BOTTOM and TOP, as long as you created the cable properly and plugged it into the correct interface on each router.  Try pinging between the routers:

TOP#ping 192.168.1.1

Sending 5, 100-byte ICMP Echos to 192.168.1.1, Timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/4 ms

Now that you have this link configured, it should be a piece of cake for you to configure the remaining serial links and Ethernet interfaces to complete the network in the picture at the top of this post.

Good luck!  Let me know if you run into any problems!