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ADSL on a 2620XM / WIC-1ADSL

fhorlaville
Level 1
Level 1

Hi !

We have a running serial link that we are replacing with an ADSL link (WIC-1ADSL).

Our new ADSL setup is a fixed IP + tunnel through which will come our public IPs.

We train, auth and get our IP ok, but that's it.

ping these doesn't work:

81.x.x.44 (fixed ADSL WAN IP)

81.x.x.1 (opposite router)

81.x.x.153 (a test server)

212.x.x.238 (tunnel destination)

10.101.25.1 (tunnel extremity)

ping 10.101.25.2 (our tunnel side) works.

What I don't understand is why we can't ping our side of the ADSL nor the opposite side (165.44 and 165.1)

Using an el-cheapo router we can surf the web.

Pointers anyone ?

THANKS !!!

>sh vers

IOS (tm) C2600 Software (C2600-IS-M), Version 12.2(15)T, RELEASE SOFTWARE (fc1)

>sh run

version 12.2

(..)

ip subnet-zero

!

(..)

no voice hpi capture buffer

no voice hpi capture destination

!

mta receive maximum-recipients 0

!

interface Tunnel1

ip address 10.101.25.2 255.255.255.252

tunnel source 81.x.x.44

tunnel destination 212.x.x.238

!

interface ATM0/0

no ip address

no ip mroute-cache

no atm ilmi-keepalive

pvc 8/35

encapsulation aal5mux ppp dialer

dialer pool-member 1

!

dsl operating-mode auto

!

interface FastEthernet0/0

ip address 192.168.237.253 255.255.255.248

(..)

!

interface Serial0/0

ip address 194.204.x.x.x.255.252

(..)

!

interface Dialer0

ip address negotiated

encapsulation ppp

no ip mroute-cache

dialer pool 1

dialer idle-timeout 0

dialer-group 1

ppp auth (..)

!

ip http server

ip classless

ip route 0.0.0.0 0.0.0.0 Serial0/0

ip route 81.x.x.x.255.255.255 Dialer0

ip route 194.x.x.x.255.255.192 192.168.237.254

ip route 212.x.x.x.255.255.255 Dialer0

!

dialer-list 1 protocol ip permit

!

snmp(..)

call rsvp-sync

!

mgcp profile default

!

dial-peer cor custom

!

line (..)

!

end

>sh int dialer 0

Dialer0 is up, line protocol is up (spoofing)

Hardware is Unknown

Internet address is 81.192.165.44/32

MTU 1500 bytes, BW 56 Kbit, DLY 20000 usec,

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

Encapsulation PPP, loopback not set

DTR is pulsed for 1 seconds on reset

Interface is bound to Vi3

(..)

Bound to:

Virtual-Access3 is up, line protocol is up

Hardware is Virtual Access interface

MTU 1500 bytes, BW 56 Kbit, DLY 100000 usec,

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

Encapsulation PPP, LCP Open

Listen: CDPCP

Open: IPCP

PPPoATM vaccess, cloned from Dialer0

Bound to ATM0/0 VCD: 1, VPI: 8, VCI: 35, loopback not set

DTR is pulsed for 5 seconds on reset

Interface is bound to Di0 (Encapsulation PPP)

(..)

All interfaces are up admin + line ...

>sh ro

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

194.204.194.0/24 is variably subnetted, 2 subnets, 2 masks

C 194.204.194.200/30 is directly connected, Serial0/0

C 194.204.194.201/32 is directly connected, Serial0/0

81.0.0.0/32 is subnetted, 3 subnets

C 81.192.165.44 is directly connected, Dialer0

C 81.192.165.1 is directly connected, Dialer0

S 81.192.207.153 is directly connected, Dialer0

10.0.0.0/30 is subnetted, 1 subnets

C 10.101.25.0 is directly connected, Tunnel1

194.204.237.0/26 is subnetted, 1 subnets

S 194.204.237.64 [1/0] via 192.168.237.254

192.168.237.0/29 is subnetted, 1 subnets

C 192.168.237.248 is directly connected, FastEthernet0/0

212.217.66.0/32 is subnetted, 1 subnets

S 212.217.66.238 is directly connected, Dialer0

S* 0.0.0.0/0 is directly connected, Serial0/0

5 Replies 5

Hello,

since you say that your ADSL WAN IP is a fixed address (81.x.x.44), can you try and assign that address to your Dialer0 interface instead of relying on ´ip address negotiated´ ?

On a side note, the reason that you cannot ping your local interface is that traffic to the local interface is redirected out to the opposite side first and then back. So if you cannot reach the other side, you cannot reach your local side either. That is a characteristic of ATM being a non-broadcast media. In e.g. Frame Relay, you would add an additional mapping to your own IP address tied to a local DLCI to accomplish the same thing.

Regards,

GP

Hi !

Thank you very much for your answer ! I forgot to mention I had tried to assign the IP, with the same results ...

Thanks for your explanation on the ATM explanation :) I would have thought that IP stack of the router would have recognized the address as being local and therefore reply to the ping itself, before sending it out to the ATM pipe, but apparently this is not the case.

Thanks again, any other ideas appreciated !

Happy new Year,

F.

have you ried to adjust MTU, on dialer interface try to set it to 1492 instead of 1500

Hi !

Thanks for the tip, it helps (i.e. makes the requests come in much faster) but it's not solved yet ...

I can now receive an IP address from two different ISPs, but i still can't ping anybody through the dialer0 interface ...

I switch from one isp to another by replacing chap by pap.

In the case of ISP1, the authentication is proxied to our own radius server so i see the requests coming in. Once it has received its IP it doesn't send any more requests and sits happily there, thinking it's connected.

any idea ? tx !

interface Dialer0

mtu 1492

ip address negotiated

ip nat outside

encapsulation ppp

dialer pool 1

dialer-group 1

ppp authentication chap callin <---- or pap callin for isp2

ppp chap hostname test@myself@isp1 <--- radius requests come to my server on another link

ppp chap password 0 test

ppp pap sent-username test2@isp2 password 0 test2

SOLVED !!!

"no cdp enable" on the dialer0 interface, or "no cdp run" on the whole router did it !

Apparently Maroc Telecom has configured CDP in a wicked way on its BAS ...

Reference:

Cisco Discovery Protocol > http://www.techexams.net/technotes/ccna/intro/cdp.shtml

I saw this using the debugging tools:

Vi2 PPP: Outbound cdp packet dropped, CDPCP state is Listen

and even though I had the same on the working Serial 0/0 interface it gave me the idea to tinker with it.

Thanks to all !