Deploying a Cisco router with WIC-1ADSL card for Internet connectivity

Why?

The main reason of having all of this is: to have a small operational lab at home, so I can practice various configuration and situations (on a smaller scale of course).

The Hardware

I have purchased two Cisco 1750 routers from eBay, having 16MB of flash and 48MB of RAM each. Included in the purchase were two WIC-1ADSL WIC cards, Cisco’s ADSLoPSTN interface.

The Software

As a minimum requirement for the WIC card, the IOS version must be at least 12.2 and the IOS feature set must be of the type C1700-Y7-MZ as number 7 in this notation means that the IOS has the ADSL feature set (c1700 = Cisco 1700 image, Y = IP feature set, 7 = ADSL feature set). Additional feature sets are available (e.g. S = IP Plus feature set, V3 = voice feature set, and more). For more information please refer to router product page.

The Network Plan

A simple home network found in any household constructed with a single switch, a wireless access point, PCs, etc…

Basic Cisco Setup

The setup is basically simple; a cable from the telco wall socket is coming through an ADSL filter and then directly connected to the WIC-1ADSL port. From services point-of-view, all I need is pure NATing (all network services like DHCP, DNS, etc… are running in my internal Compaq server). So the configuration is pretty simple, do ADSL connectivity, do NATing, and that’s all.
Note: for initial configuration to be done (assuming the router is not configured previously, a serial console cable is needed and the entire configuration is done through it).

IOS Configuration

Let’s begin with the configuration; entering global configuration area is straight forward command:

router1#conf t

In my situation, DHCP service is not needed in the router, this command is issued in the global configuration area:

router1(config)#no service dhcp

Then as I have DNS service up and running on my Compaq server, the following command points the router to the default DNS I am using:

router1(config)#ip name-server xxx.xxx.xxx.xxx

xxx.xxx.xxx.xxx is the IP address of my Compaq server.
Now it is the time to configure the ATM port (my provider has PPPoA 8.35 ADSL connectivity so change this according to your provider’s values), these commands are issued:

router1(config)#int atm0
router1(config-if)#no ip address
router1(config-if)#no ip mroute-cache
router1(config-if)#no atm ilmi-keepalive
router1(config-if)#dsl operating-mode auto
router1(config-if)#hold-queue 244 in
router1(config-if)#pvc 8/35

Notice that after issuing the last command – pvc 8/35 – the prompt changes to:

router1(config-if-atm-vc)#

Then, continuing with the following commands:

router1(config-if-atm-vc)#encapsulation aal5mux ppp dialer
router1(config-if-atm-vc)#dialer pool-member 1
router1(config-if-atm-vc)#exit
router1(config-if)#exit

Issuing exit command twice will return back to the global configuration area and the prompt will return back to:

router1(config)#

FastEthernet interface needs an entry for NATing, the following commands are issued:

router1(config)#int f0
router1(config-if)#ip nat inside
router1(config-if)#exit
router1(config)#

Now Dialer1 interface has to be configured, these commands will configure it:

router1(config)#int dialer1
router1(config-if)#ip address negotiated
router1(config-if)#ip access-group dialer-in in
router1(config-if)#ip nat outside
router1(config-if)#encapsulation ppp
router1(config-if)#dialer pool 1
router1(config-if)#no cdp enable
router1(config-if)#ppp pap sent-username your-username password your-password
router1(config-if)#exit
router1(config)#

your-username and your-password here represent the actual credentials given by the service provider, replacing them directly. Again, after issuing exit command the prompt returns to the global configuration area.
Now, continuing with the following commands in the global configuration area:

router1(config)#ip nat inside source list 1 interface Dialer1 overload
router1(config)#access-list 1 permit xxx.xxx.xxx.0 0.0.0.255
router1(config)#access-list 1 deny any
router1(config)#dialer-list 1 protocol ip permit
router1(config)#ip route 0.0.0.0 0.0.0.0 Dialer1
router1(config)#ip access-list extended dialer-in
router1(config-ext-nacl)#deny ip host 0.0.0.0 any
router1(config-ext-nacl)#deny ip 10.0.0.0 0.255.255.255 any
router1(config-ext-nacl)#deny ip 127.0.0.0 0.255.255.255 any
router1(config-ext-nacl)#deny ip 169.254.0.0 0.0.255.255 any
router1(config-ext-nacl)#deny ip 172.16.0.0 0.15.255.255 any
router1(config-ext-nacl)#deny ip 192.168.0.0 0.0.255.255 any
router1(config-ext-nacl)#deny ip 224.0.0.0 31.255.255.255 any
router1(config-ext-nacl)#permit ip any any
router1(config-ext-nacl)#exit
router1(config)#exit
router1#

The xxx.xxx.xxx.0 is the network address being used internally.

By now, the router should be negotiating ADSL, once it is up, the Internet is connected within seconds (provided that everything is correct including username & password). A test contecting to the Internet is done using any PC directly connected to the internal network.

Conclusion

As this part is done without any problems, my internal network enjoying the Internet by all means.