Cisco Configuring ATM interface

Posted on 2013-05-13
Last Modified: 2013-06-01
Hello Experts

Can an expert point me to where I can find information on configuring ATM interfaces on ISR G2 1921?

Question by:cpatte7372
  • 3
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Expert Comment

ID: 39162365
Could you give a little more info? I assume you are trying to establish a PPP connection to your ISP over (A)DSL?

Author Comment

ID: 39164173

Thanks for responding. I've never configured this type of interface before. I'm not even sure what questions I need to be asking. However, yes I am trying to establish a PPP connection to our ISP over DSL?.

Can you or any expert provide some guidance?


Accepted Solution

iammorrison earned 500 total points
ID: 39164881
Have you configured dialer interfaces before? Typically, the actual ATM interface requires minimal config to get up and running:

conf t
int ATM0
no ip address
no atm-ilmi-keepalive
pvc 0/35 <---- the Private Virtual Circuit number varies between ISPs, you should confirm
pppoe-client dial-pool-number 1 dial-on-demand
dsl operating-mode auto <---- this is optional, leave it out at first but sometimes it helps.

And that should be it, then configure your Dialer interface and you should good!
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Author Comment

ID: 39167570

Thanks for responding. I should mention that we use BT as our ISP and they specify not to use pppoe, but instead use pppoa. The current config on the interface is:

interface ATM0/0/0
 no ip address
 no atm ilmi-keepalive
 pvc 0/35
  encapsulation aal5mux ppp dialer

And the current configuration on the dialer interface is:

interface Dialer1
 ip address
 encapsulation ppp
 ppp chap hostname xxxxxxxxxxxxxxxxxxxx
 ppp chap password 0 xxxxxxxxxxxxxxx

However, I can't ping google on

The full configuration is attached

Your (or any expert)  would be greatly appreciated.


Expert Comment

ID: 39167968
A couple of quick things:

You are certain you are using CHAP and not PAP authentication?

You have not dictated your outside NAT interface (usually your dialer interface)

on the dialer interface add:
no ip redirects
no ip unreachables
ip nat outside
ip virtual-reassembly
dialer pool 1
dialer-group 1
no cdp enable

on the ATM interface add:

dsl operating-mode auto
dial-pool-number 1

hope that helps!

Author Closing Comment

ID: 39213445

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