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New Member

851 config help!

Hey there,

I purchased an 851 non-wireless router a few months ago. I have tried to configure it using SDM, CNA and CLI. I can connect and alter and upload new configurations without problems.

My issue is the configuration itself! I have gone through countless tutorials, how-to's, examined sample files, etc, and I cannot seem to get it working properly.

My setup is very simple: I have a linksys cable modem. I want to connect the 851 directly to this, and my computer to the 851. I need to be able to connect to the internet through this setup. I want to be able to plug other computers and a wireless router into the 851 at will, and have them connect to the internet as well. If I can get this far, then I will start putting ACL's in place to secure the thing to some extent.

This behavior has been 'default' in every other small router I have worked with, but not the 851.

I really am trying!

I am attaching my current config.

Thanks for any help you folks can offer.


cisco 851 config file


Re: 851 config help!

Hi chris ,

I 851 router the fastethernet ports 0-3 are switch port , u have created interface VLAN 10 , enable switch port access VLAN 10 for all three fastethernet port 0-3 , They u can able connect to internet cloud .

New Member

Re: 851 config help!

Looks like you need to addd the following:

config t


interface vlan1

ip nat inside


Everything else looks ok. If that doesn't work, there are a few things you should check.

1. From the CLI, enter the following from enable mode (MyRouter#): show ip interface brief

Ensure that the FA4 interface does have an IP address assigned.

2. show ip nat translation

You should see the address of your computer translated to the address of your FA4 interface IP address. (you might need to attempt a ping from your pc first).

If both of those things are there and it still doesn't work, let me know.

New Member

Re: 851 config help!

Thank you very much. I will make these changes and report back.