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New Member

Cisco 2921 router issue with ADSL modem

Hi All,

We have one ADSL modem which is synced with ISP. When I set modem as DHCP mode, it can get static IP assigned from ISP fine. I would like set up IP address on our router interface. So I set up modem as bridge mode. I see the DSL line is up. Configure the PPoE part under Gi0/0 interface and Dialer 0 interface is configured too. But when I debug it, it only shows "Sending PADI:" and "padi timer expired" log. So ISP never responds. The configuration is listed below. I see modem use LLC based multiplexing. Since modem can get IP so it must be something missing in my router setup. Or different from the modem. Please help. Thank you!

interface GigabitEthernet0/0

ip tcp adjust-mss 1440

duplex auto

speed auto

pppoe enable group global

pppoe-client dial-pool-number 1

interface Dialer0

ip address negotiated

no ip redirects

no ip unreachables

ip mtu 1492

ip virtual-reassembly in

encapsulation ppp

dialer pool 1

dialer-group 1

ppp authentication pap chap callin

ppp chap hostname xxx@xxx

ppp chap password 7xxxxxx

ppp pap sent-username xxx@xxx password 7 xxxxxx

ppp ipcp address accept

dialer-list 1 protocol ip permit



Cisco 2921 router issue with ADSL modem

d oyou see in log that Vi interface goes UP unad DOWN?

what does the command  show "show pppoe session" ?

It looks that your modem don't "forward" the  PPPoE packets yet.

New Member

Re: Cisco 2921 router issue with ADSL modem

Thanks Konstantin for answering my question. I see the Vi always up/up. No flaping. The show pppoe session and pppoe statistics show all the number as 0. In addition, show ppp interface dial 0 and vi 1 shows the interface state is down:

router#sh pppoe session

     1 client session

Uniq ID  PPPoE  RemMAC          Port                    VT  VA         State

           SID  LocMAC                                      VA-st      Type

    N/A      0  0000.0000.0000  Gi0/1                   Di0 N/A        PADISNT


router#sh pppoe statistics

PPPoE Events                   TOTAL         SINCE CLEARED

------------------------------ ------------- -------------

INVALID                        0             0

PRE-SERVICE FOUND              0             0

PRE-SERVICE NONE               0             0

SSS CONNECT LOCAL              0             0

SSS FORWARDING                 0             0

SSS FORWARDED                  0             0

SSS MORE KEYS                  0             0

SSS DISCONNECT                 0             0

SSS DISCONNECT ACK             0             0

CONFIG UPDATE                  0             0

STATIC BIND RESPONSE           0             0

PPP FORWARDING                 0             0

PPP FORWARDED                  0             0

PPP DISCONNECT                 0             0

PPP RENEGOTIATION              0             0

SSM PROVISIONED                0             0

SSM UPDATED                    0             0

SSM ACCT STATS UPDATED         0             0

SSM DISCONNECT                 0             0

                               0             0

PPPoE Statistics               TOTAL         SINCE CLEARED

------------------------------ ------------- -------------

SSS Request                    0             0

SSS Response Stale             0             0

SSS Disconnect                 0             0

PPPoE Handles Allocated        0             0

PPPoE Handles Freed            0             0

Dynamic Bind Request           0             0

Static Bind Request            0             0

SSM Async Stats Request        0             0

ATM VCD Retrieval Errors       0             0

PADX Retrieval Errors (sync)   0             0

PADR Processing Errors (sync)  0             0

Base VA Create Errors (sync)   0             0

Call Admin Drops               0             0

Max PADR Size Pkts             0             0

Bad MAC Addr                   0             0

Bad Cookie                     0             0

Bad Service Name               0             0

Max Sess Reach                 0             0

Dup PADRs Rcvd                 0             0

Memory Fails                   0             0

Tags Processing Errors         0             0

BBA Grp Errors                 0             0

MAC Elem Errors                0             0

Vlan Cfg Fails                 0             0

Vlan Id Mismatchs              0             0

Invalid Versions               0             0

Null Sess Ids                  0             0

Malformed PADX Received        0             0

Invalid Tag Ignored            0             0

router#sh ppp int dialer 0

PPP Serial Context Info


Interface        : Di0

PPP Serial Handle: 0x0

PPP Handle       : 0x0

SSS Handle       : 0x0

AAA ID           : 0

Access IE        : 0x0

SHDB Handle      : 0x0

State            : Down

Last State       : Init

Last Event       : RestartTimeout

router#sh ppp int virtual-Access 1

PPP Serial Context Info


Interface        : Vi1

PPP Serial Handle: 0x0

PPP Handle       : 0x0

SSS Handle       : 0x0

AAA ID           : 0

Access IE        : 0x0

SHDB Handle      : 0x0

State            : Down

Last State       : Init

Last Event       : None

New Member

Cisco 2921 router issue with ADSL modem

Hi hxmengmetro, I couldn't see the default route (or any other route) in your configuration. If you don't configure it, you must add in order to interested traffic go out and to start PPP negotiation.

ip route dialer 0

Hope this helps


New Member

Cisco 2921 router issue with ADSL modem

Thanks for this information.

I have configured one specific route to the gateway:

ip route Dialer0

I tried to ping the gateway from router, but still didn't see the pppoe negotiation process started.


New Member

Re: Cisco 2921 router issue with ADSL modem

I finally figured out the configuration through CLI for the ADSL modem last Friday. After I correctly configured it, the ethernet interface got IP assigned by ISP. Everything is looking good now. Thanks guys!

What did you change in our

What did you change in our ADSL modem? I'm having the exactly same issue.

Hi Kenshaozinho, Please post

Hi Kenshaozinho,


Please post your sanitized configs for review.