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Community Member

Issue configuring Soho97 - ADSL with pppoa

I'm trying to configure my soho97 router with adsl, but it doesn't works. I'm in the UK with a fixed IP address and using pppoa, chap, vc-mux and pvc 0/38.

from the internal lan I can ping int e0( and int d1(82.x.x.x) with no issues, but 1 cannot the isp’s dns server

from the router console I can only ping with success. int d1 and isp dns no good..

Sample below

Building configuration...

Current configuration : 1685 bytes


version 12.3

no service pad

service timestamps debug uptime

service timestamps log uptime

service password-encryption


hostname RouterSOHO97


ip subnet-zero

ip name-server 212.x.8.1

ip name-server

ip dhcp excluded-address


ip dhcp pool CLIENT



dns-server 212.x.x.x.23.8.6

lease 0 2



no aaa new-model


interface Ethernet0

ip address 10.10.x.x.255.255.0

ip nat inside

ip tcp adjust-mss 1452

hold-queue 100 out


interface ATM0

no ip address

atm vc-per-vp 128

no atm ilmi-keepalive

pvc 0/38

encapsulation aal5mux ppp dialer


dsl operating-mode auto


interface Dialer1

ip address 82.x.x.x

ip mtu 1492

ip nat outside

encapsulation ppp

ip tcp adjust-mss 1452

dialer pool 1

dialer-group 1

ppp authentication chap pap callin

ppp chap hostname xxxxxx

ppp chap password xxxx

ppp pap sent-username xxxxxx password xxxx!

ip nat inside source list 102 interface Dialer1 overload

ip classless

ip route Dialer1

ip http server

no ip http secure-server


access-list 23 permit

access-list 102 permit ip any

dialer-list 1 protocol ip permit


line con 0

exec-timeout 120 0

no modem enable

stopbits 1

line aux 0

line vty 0 4

access-class 23 in

exec-timeout 120 0

login local

length 0


scheduler max-task-time 5000



Below some diags samples;

show int atm 0

ATM0 is up, line protocol is up

Hardware is PQUICC_SAR (with Alcatel ADSL Module)

MTU 1500 bytes, sub MTU 1500, BW 288 Kbit, DLY 80 usec,

reliability 68/255, txload 1/255, rxload 1/255

Encapsulation ATM, loopback not set

Encapsulation(s): AAL5 AAL2, PVC mode

10 maximum active VCs, 128 VCs per VP, 1 current VCCs

VC Auto Creation Disabled.

VC idle disconnect time: 300 seconds

Last input never, output 00:14:02, 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

0 packets input, 0 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

16 packets output, 1120 bytes, 0 underruns

0 output errors, 0 collisions, 3 interface resets

0 output buffer failures, 0 output buffers swapped out


sh atm int atm0

Interface ATM0:

AAL enabled: AAL5 AAL2, Maximum VCs: 10, Current VCCs: 1

Maximum Transmit Channels: 0

VCIs per VPI: 128,

Max. Datagram Size: 1528

PLIM Type: ADSL - 800Kbps Upstream, DMT, TX clocking: LINE

0 input, 16 output, 0 IN fast, 0 OUT fast

Avail bw = 800

Config. is ACTIVE


sh ip int bri

Interface IP-Address OK? Method Status Protocol

ATM0 unassigned YES NVRAM up up

Dialer1 82.x.x.x YES manual up up

Ethernet0 YES NVRAM up up


Sorry for the large amount of info. hopefully it will help solve my problems..



VIP Purple

Re: Issue configuring Soho97 - ADSL with pppoa


from what I can see you need to bind your ATM interface to your dialer:

interface ATM0

no ip address

atm vc-per-vp 128

no atm ilmi-keepalive

pvc 0/38

encapsulation aal5mux ppp dialer

-->dialer pool-member 1

Can you add this to your configuration and see if it works ?



Community Member

Re: Issue configuring Soho97 - ADSL with pppoa


Thanks for your advice.

I have tried your suggestion and I still have the same symptons??


Community Member

Re: Issue configuring Soho97 - ADSL with pppoa

further on from that i ran "debug ppp negotiation" and i attached the output. there is an Authentication failure. could this be the isp issue.

thanks in advance


Community Member

Re: Issue configuring Soho97 - ADSL with pppoa

Thanks for all your help.

It wasn't anything to with my configs. My account was incorrectly configured at my ISP.


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