ADSL setup on 827H router

Unanswered Question
May 21st, 2007
User Badges:

Hi All,

I'm trying to setup an ADSL connection on an 827H router. The settings for the connection according to the ISP are:

Mode = RFC 1483 Routing

VPI = 0 VCI = 34


Multiplexing = LLC

Encapsulation = AAL5 Snap

The connection is currently up and running with these settings on a very cheap modem/router. It gets an IP from the ISP by DHCP without specifying an username/password. I'm trying to migrate the connection to the 827H. This is what I,ve configured:


interface ATM0

mac-address 0005.b409.2528

no ip address

no atm ilmi-keepalive

dsl operating-mode auto


interface ATM0.1 point-to-point

ip address dhcp

no snmp trap link-status

pvc 0 0/34


encapsulation aal5snap


The MAC I'm specifying is the MAC that the current modem/router is using, so that the ISP does not need to refresh. The connection seems to come up on the ATM side of things:

Router#sh int atm0

ATM0 is up, line protocol is up

Hardware is PQUICC_SAR (with Alcatel ADSL Module)

MTU 1500 bytes, sub MTU 1500, BW 928 Kbit, DLY 80 usec,

reliability 152/255, txload 1/255, rxload 1/255

Encapsulation ATM, loopback not set

Encapsulation(s): AAL5 AAL2, PVC mode

10 maximum active VCs, 1024 VCs per VP, 1 current VCCs

VC Auto Creation Disabled.

VC idle disconnect time: 300 seconds

Last input never, output 00:00:08, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: Per VC Queueing

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

3 packets input, 246 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

66 packets output, 30464 bytes, 0 underruns

0 output errors, 0 collisions, 4 interface resets

0 output buffer failures, 0 output buffers swapped out


But I don't seem to get an IP address:

Router#sh ip int brief

Interface IP-Address OK? Method Status Prot


Ethernet0 YES NVRAM up up

ATM0 unassigned YES NVRAM up up

ATM0.1 unassigned YES DHCP up up

Attached you will find some output of the debug atm events and dhcp detail command. Any Ideas? Thanks in advance for your help.

Best regards,


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
paolo bevilacqua Mon, 05/21/2007 - 16:54
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member


possibly the ISP is expecting briding mode so you would need to configure

bridge irb

int atm0.1

no ip address

bridge-group 1

int bvi1

ip address dhcp

ip nat inside

firestartest Thu, 07/12/2007 - 07:38
User Badges:


Did you get this sorted? I have a Cisco 877w with the same problem. I cannot obtain a DHCP address.



This Discussion