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Cisco 1721 configuration (newbie)

marcelocbf
marcelocbf asked
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Last Modified: 2010-04-17
Hi guys,

I've just bought an used Cisco 1721 to try to learn. But I'm stuck. I've already read the questions on the kb, but I'm still stuck here.

I'm trying to connect the router to my cable modem (Provider: Comcast). I have a Linksys router and I got all the configuration like IP, subnet, DNS, default gateway from the current working configuration on that.

So, I replaced the router with my 1721. It has a WIC-1ENET already installed. I consoled into the cisco and configured the Ethernet 0 port with the IP address and subnet that I got from the Linksys, and set the IP 192.168.1.1 255.255.255.0 to the FastEthernet 0 port that goes to my network. I have set the default gateway and the DNS address (I think that this part I've set with the right command. I'm not sure) w/ the current configuration. I rebooted ... but it doesn't work .... I don't how to test it out ... But from the console I tried to ping my network .. and it is ok ... But when I try to ping and external address, I have no success.

Can you please ... show me what I'm doing wrong ?

Thanks,

Marcelo

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While you are on the console, do a 'show run' and paste that output here;

Cheers,
Rajesh
Instructor
CERTIFIED EXPERT
Top Expert 2015
Commented:
Couple things to start:

First; Unless you have a static IP address from Comcast, you're going to have to set the IP address of the interface that connects to the cable modem to DHCP.

Second; If Comcast is registering your MAC address, then you'll either need to set the MAC of the Cisco to the same as the Linksys or have Comcast clear the registration of your existing MAC.

Third (and final... for now); Do you have NAT enabled?

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Commented:
Thanks donjohnston ...
You were right ... I set the ip to get via DHCP and cloned the MAC address ...
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