Dynamic DSL on cisco router 877

Kevin Xau · ‎12-09-2012

Hi,

I have one Dynamic DSL line, this line plug to the Dlink router can work properly. But for some reason, we need to change to the cisco 877 router, when I conenct this line to the cisco router, it cannot work, the configuration seems incorrect. Below is the configuration:

version 12.3

no service pad

service tcp-keepalives-in

service tcp-keepalives-out

service timestamps debug datetime msec localtime show-timezone

service timestamps log datetime msec localtime show-timezone

service password-encryption

service sequence-numbers

!

hostname router-877

!

boot-start-marker

boot-end-marker

!

no aaa new-model

!

username admin password 7 5sg234kjasjdb

!

ip subnet-zero

no ip source-route

ip cef

!

no ip bootp server

!

interface ATM0

no ip address

no ip redirects

no ip unreachables

no ip proxy-arp

ip route-cache flow

no atm ilmi-keepalive

dsl operating-mode auto

!

interface ATM0.1 point-to-point

pvc 0/100

pppoe-client dial-pool-number 1

!

interface Vlan1

description LAN

ip address 172.16.0.200 255.255.255.0

no ip redirects

no ip unreachables

no ip proxy-arp

ip nat inside

ip virtual-reassembly

ip tcp adjust-mss 1412

!

interface Dialer1

description Internet DSL access

ip address negotiated

no ip redirects

no ip unreachables

no ip proxy-arp

ip mtu 1452

ip nat outside

ip virtual-reassembly

encapsulation ppp

dialer pool 1

dialer-group 1

no cdp enable

ppp authentication chap pap callin

ppp chap hostname company@abc.net

ppp chap password 7 6tmsadvdvk3352gd

ppp pap sent-username company@abc.net password 7 6tmsadvdvk3352gd

!

ip classless

ip route 0.0.0.0 0.0.0.0 Dialer1

!

ip nat inside source list 10 interface Dialer1 overload

!

access-list 10 permit 172.16.0.0 0.0.0.255

!

line con 0

line aux 0

line vty 0 4

!

end

Please advice where I configure wrong. Thanks

cadet alain · ‎12-09-2012

Hi,

What is the output of sh ip int br and sh ip route ?

Regards.

Alain

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Kevin Xau · ‎12-09-2012

Hi,

Router-877# sh ip int brief

Interface IP-Address OK? Method Status Protocol

FastEthernet0 unassigned YES unset up up

FastEthernet1 unassigned YES unset up down

FastEthernet2 unassigned YES unset up down

FastEthernet3 unassigned YES unset up down

ATM0 unassigned YES manual down down

ATM0.1 unassigned YES unset down down

Vlan1 172.16.0.200 YES manual up up

NVI0 172.16.0.200 YES unset up up

Dialer1 unassigned YES manual up up

Router-877#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

ia - IS-IS inter area, * - candidate default, U - per-user static route

o - ODR, P - periodic downloaded static route

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

172.16.0.0/24 is subnetted, 1 subnets

C 172.16.0.0 is directly connected, Vlan1

S* 0.0.0.0/0 is directly connected, Dialer1

cadet alain · ‎12-09-2012

Hi,

shut atm interface then enable debug like this:

enable

debug ppp negotiation

debug ppp authentication

conf t

no service timestamp debug

logging on

logging buffered debug

logging console info

do clear log

int atm

no shut

do sh log

Post the output here.

Regards.

Alain

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Kevin Xau · ‎12-09-2012

Hi,

After I enable the debug as you suggest, below is the output for "do sh log" command:

Router-877(config)#do sh log

Syslog logging: enabled (1 messages dropped, 0 messages rate-limited,

0 flushes, 0 overruns, xml disabled, filtering disabled)

No Active Message Discriminator.

No Inactive Message Discriminator.

Console logging: level informational, 26 messages logged, xml disabled,

filtering disabled

Monitor logging: level debugging, 0 messages logged, xml disabled,

filtering disabled

Buffer logging: level debugging, 2 messages logged, xml disabled,

filtering disabled

Logging Exception size (4096 bytes)

Count and timestamp logging messages: disabled

Persistent logging: disabled

No active filter modules.

ESM: 0 messages dropped

Trap logging: level informational, 30 message lines logged

Log Buffer (4096 bytes):

000026: *Dec 10 06:12:49.883 UTC: %LINK-3-UPDOWN: Interface ATM0, changed state to down

000027: *Dec 10 06:12:53.923 UTC: %SYS-5-CONFIG_I: Configured from console by console

Router-877(config)#

cadet alain · ‎12-10-2012

Hi,

I don't see any shut/no shut on the ATM , did you do this?

This should then start PPP negotiation and you should see it in the log output.

Regards.

Alain

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Kevin Xau · ‎12-10-2012

Hi,

I have shut/no shut the ATM interface, but no thing display.

cadet alain · ‎12-10-2012

Hi,

Can you shut/no shut the dialer interface and tell me if you see logs ?

Regards.

Alain

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Kevin Xau · ‎12-10-2012

Hi,

I also shut/no shut the dial 1 interface, but still no thing display except I execute command: do sh log, the content same above log I post.

No Inactive Message Discriminator.

Console logging: level informational, 44 messages logged, xml disabled,

filtering disabled

Monitor logging: level debugging, 0 messages logged, xml disabled,

filtering disabled

Buffer logging: level debugging, 1 messages logged, xml disabled,

filtering disabled

Logging Exception size (4096 bytes)

Count and timestamp logging messages: disabled

Persistent logging: disabled

No active filter modules.

ESM: 0 messages dropped

Trap logging: level informational, 48 message lines logged

Log Buffer (4096 bytes):

000047: *Dec 10 06:47:44.083 UTC: %LINK-3-UPDOWN: Interface Dialer1, changed sta

te to up

cadet alain · ‎12-10-2012

Hi,

do you hit enter to get all log output ?

Regards.

Alain

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Kevin Xau · ‎12-10-2012

Hi,

Yes. After I execute the command: do sh log, I press "space" key to load all output and copy it to this post. above is the all output log.

cadet alain · ‎12-10-2012

Hi,

http://www.cisco.com/en/US/tech/tk175/tk15/technologies_configuration_example09186a008071a69d.shtml

What are the results ?

Regards.

Alain

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Giuseppe Larosa · ‎12-10-2012

Hello Gia,

it looks like you have an OSI physical layer issue

ATM0 unassigned YES manual down down

ATM0.1 unassigned YES unset down down

Follow the document provided by Alain at the point

>>If the ATM interface is down and down—not administratively down—check the pinout of your DSL wall jack. The DSL Router uses a standard RJ-11 (4-pin or 6-pin) cable in order to provide the ADSL connection to the wall jack. The center pair of pins on the RJ-11 cable are used to carry the ADSL signal (pins 3 and 4 on a 6-pin cable, or pins 2 and 3 on a 4- pin cable). This does not apply to the Cisco 1417 which uses pins 2 and 5.

If you are sure you have the right pins on the wall jack and the ATM0 interface is still down and down, replace the RJ-11 cable between the DSL port and your wall jack. If the interface is still down and down after you replace the RJ-11 cable, contact your ISP and have the ISP verify that ADSL service has been enabled on the wall jack that you use.

Hope to help

Giuseppe

Kevin Xau · ‎12-10-2012

Hi,

This DSL line is work properly when I connect to the Dlink router, but it is not worked with Cisco 877. And based on this information:

Is the carrier detect (CD) light on the front panel of the Cisco DSL Router on or off?

If the CD light is on, go to the Layer 2 Issues section of this document.

If the CD light is off, continue with the next question.

I have checked on the cisco 877 router, the CD light is on.

When I come to the layer 2 issues, although I enable all debug as Alain recommend, but no thing display.

Thanks.

Giuseppe Larosa · ‎12-10-2012

Hello Gia,

if ATM interface state is down/down PPPoA negotiation does not start and nothing is displayed on the log.

I agree that the CD LED should be off if ATM interface is down/down.

However, the interface is down so my guess is a physical layer issue.

Hope to help

Giuseppe