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PIX 501 and internet access issue

My network is very simple, like this: A DSL Modem is connected to a Cisco PIX 501 firewall/router, and a computer is connected to this firewall.

Now this PIX 501 box has two interfaces: Inside ( and the netwroked PC ( The outside interface is set to DHCP to be dynamically assigned an IP by the ISP's DNS server (

My networked PC (running Windows XP) is configured with an static IP (, default Gateway ( which is the PIX 501), and the DNS IP ( which is the ISP's DNS Server).

But I can NOT access the internet. I can Ping (the inside interface) but not the outside (

What am I missing and what should I do?


Please note:

I attached a file which shows the current PIX config. Please refer to the attachment below.





Re: PIX 501 and internet access issue

Hi .. the config seems Ok .. but I believe you are doing doble NATing.

1.- As packets go from inside to outside (PIX)

2.- As packest go from PIX and out of the Modem.

I suggest you to try configuring your modem in bridge mode and the PIX as PPPoE client.

Here is an example you could use as reference.

I hope it helps .. please rate if it does !!

Community Member

Re: PIX 501 and internet access issue

Thanks for the help.

It is too complex for me to follow. The important thing is: this PIX used to work. It is just recently I moved from the one place to another. After I re-hooked up the network, it stopped working, even though I went through a lot of the re-starting, re-booting,...



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