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ADSL PPPoA bridge w/WIC-1ADSL configuration on a 2611

I currently have a Cisco 2611 (12.3) that is connected to a Zyxel ADSL modem. The router provides NAT/VPN and firewalling for the internal network.

I have purchased a WIC-1ADSL to replace the Zyxel, but before I install, I'm trying to understand the configuration options I have.

My ISP provided me with the VPI/VCI info (0/35) and the fact that they are running PPPoA in bridged mode.

This makes sense to me with the external Zyxel device connected to the circuit and then to my router...but how does this work when the "bridge" is internal to the Cisco router itself? Where are my public IP addresses and what interface will they be assigned to for routing to the internal, private network?

Can someone explain this to me or point me to documents that will help me understand this?

Thanks much,



Re: ADSL PPPoA bridge w/WIC-1ADSL configuration on a 2611

Here is a useful URL that shows different configurations for your setup.

Community Member

Re: ADSL PPPoA bridge w/WIC-1ADSL configuration on a 2611

Yes, thanks. I had already downloaded that pdf some time ago, but it was confusing to me with regard to where the public IP addresses are configured in a pure bridge mode config.

Once I got the module installed, things started to make more sense. The only problem I had after that was the fact that the documentation uses "ATM0" instead of what it should be is "ATM0/0" ...

After a few minutes and re-reading the RFC1483 Bridging config again, I realize that the public IP addresses are on the virtual bridging interface, and once I transfered all of my configurations, crypto, nat, etc. from the original ethernet i/f to the BVI i/f...I was up and running!

Thanks much for your assistance.

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