09-29-2008 11:48 AM - edited 03-03-2019 11:44 PM
I have a static IP from AT&T for an ADSL connection. My router is an 1841 with an ATM (with ADSL module). I have a username and password and the IP/mask/gw from AT&T but I'm not sure if I have my config correct. All the interfaces that I think are involved show up, up.
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10-07-2008 09:30 AM
Hello Jason,
here is a config for PPPoE over ATM PVC
PPPoEoA Client Configuration Example
The following example shows how to configure the PPPoE client DDR idle-timer on an ATM PVC interface:
!
vpdn enable
no vpdn logging
!
vpdn-group 1
request-dialin
protocol pppoe
!
interface ATM0/1/0
pvc 0/35
pppoe-client dial-pool-number 1 dial-on-demand
!
interface Dialer1
ip address x.x.x.x
! what must be
ip mtu 1492
encapsulation ppp
dialer pool 1
dialer idle-timeout 180 either
dialer hold-queue 100
dialer-group 1
! other ppp auth commands here
!
dialer-list 1 protocol ip permit
!
ip route 0.0.0.0 0.0.0.0 Dialer1
You need to adapt it to your case where the ip address is static and not negotiated and to find out the ppp authentication config under dialer interface
Hope to help
Giuseppe
09-29-2008 11:56 AM
Hello Jason,
if AT&T provides a static ip address how can be the ip address negotiated as in your config ?
probably you just need to configure IPv4 over aal5snap
int atm0
ip address x.x.x.x 255.255.255.255
pvc 0/35
encapsulation aal5snap
protocol ip x.x.x.y broadcast
without using a dialer or at least you need to assign the ip address as per specification inside dialer config
Hope to help
Giuseppe
09-29-2008 02:46 PM
I changed the interface configs but it still doesn't work.
interface ATM0/1/0
ip address 71.x.x.49 255.255.255.248
ip nat outside
ip virtual-reassembly
no atm ilmi-keepalive
dsl operating-mode auto
crypto map to_vpn
pvc 0/1
encapsulation aal5autoppp Dialer0
dialer pool-member 1
!
!
interface Virtual-Template2
no ip address
!
interface Dialer0
no ip address
ip virtual-reassembly
encapsulation ppp
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication chap callin
ppp chap hostname blahblah@blah.net
ppp chap password xxx
ppp pap sent-username blahblah@blah.net password 7
10-04-2008 12:15 AM
Hello Jason,
two notes:
it is unlikely that the right VPI/VCI is 0/1 because ATM standard reservers for the network values 0/1-31 : the first usable PVC is 0/32.
Check with the provider what values you need to use.
b)
if you assign an IP address to the ATM interface you need to change the pvc encapsulation:
pvc 8/35
enc aal5snap
you probably don't need the dialer and virtual-template sorry if I was unclear in previous post
I'm a little confused : usually ip address is dynamically assigned during ppp negotiation.
When a static ip address is provided the config is different as described above and is classical IPv4 over ATM.
You need to clarify with the provider what type of ADSL service they are giving you.
Hope to help
Giuseppe
10-06-2008 06:37 AM
I changed the config per your suggestion but it still doesn't seem to be working. AT&T's support is pretty useless when trying to get the information I need. They tell me they are not trained to help configure a Cisco router with ATM WIC.
interface ATM0/1/0
ip address 71.142.18.49 255.255.255.248
ip nat outside
ip virtual-reassembly
no atm ilmi-keepalive
dsl operating-mode auto
crypto map to_vpn
pvc 8/35
encapsulation aal5snap
No dialer interface and no virtual interface
10-06-2008 08:36 AM
I spoke to a level 2 tech at AT&T and he told me I need to use PVC 0/35 and the router must authenticate before it can use the static IP so I believe I need a dialer interface.
Here is my config now but it is still not working. I've attached a show int.
interface ATM0/1/0
no ip address
ip nat outside
ip virtual-reassembly
no atm ilmi-keepalive
dsl operating-mode auto
crypto map to_vpn
pvc 0/35
dialer pool-member 1
protocol ppp dialer
!
!
interface Dialer0
no ip address
ip virtual-reassembly
encapsulation ppp
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication chap callin
ppp chap hostname norcalrehab1@sbcglobal.net
ppp chap password 7 11071C1D0317075D
ppp pap sent-username norcalrehab1@sbcglobal.net password 7 09424B110D001B43
10-06-2008 09:13 AM
Hello Jason,
this is a step further
I would try the following:
int atm0/1/0
no ip nat outside
! all L3 config under dialer0 and set the ip address to the one provided
int dialer0
ip address 71.142.18.49 255.255.255.248
! use the static address they have provided
ip nat outside
! nat outside here
then
int atm0/1/0
shut
term mon
debug ppp negotiation
debug ppp authentication
int atm0/1/0
no shut
collect the output and post it as a text file
term no mon
undebug all
Hope to help
Giuseppe
10-06-2008 01:52 PM
10-06-2008 02:16 PM
Hello Jason,
O : output tx frames
I : input rx frames
no one is sending any form of PPP frame to your router. you can never see a I frame in this debug output.
Try to contact again the person that has given you about the right VPI/VCI and ask what form of PPP they want
PPPoA over ATM
PPPoEoA = pppoE over ATM
configurations and ATM encapsulations are different in the two cases
Your current config is the first one.
Hope to help
Giuseppe
10-07-2008 06:32 AM
they do PPPOE so I guess I need to do PPPoEoA
10-07-2008 09:30 AM
Hello Jason,
here is a config for PPPoE over ATM PVC
PPPoEoA Client Configuration Example
The following example shows how to configure the PPPoE client DDR idle-timer on an ATM PVC interface:
!
vpdn enable
no vpdn logging
!
vpdn-group 1
request-dialin
protocol pppoe
!
interface ATM0/1/0
pvc 0/35
pppoe-client dial-pool-number 1 dial-on-demand
!
interface Dialer1
ip address x.x.x.x
! what must be
ip mtu 1492
encapsulation ppp
dialer pool 1
dialer idle-timeout 180 either
dialer hold-queue 100
dialer-group 1
! other ppp auth commands here
!
dialer-list 1 protocol ip permit
!
ip route 0.0.0.0 0.0.0.0 Dialer1
You need to adapt it to your case where the ip address is static and not negotiated and to find out the ppp authentication config under dialer interface
Hope to help
Giuseppe
10-07-2008 09:42 AM
I will try that config and let you know. AT&T did say that the IP is "sticky static," meaning the IP is reserved for my router but it will be negotiated based on the credentials I have. For other AT&T connections I've configured I had to put username/password in but leave the address as negotiated.
10-07-2008 11:03 AM
I tried the config and I think we are almost there. Attached is the current config along with the debug output.
When I put the static IP on the dialer interface nothing happened but when I made the dialer negotiate it worked, mostly. I'm not getting the static IP I was told was assigned to me and after a few minutes I lose the IP and have to shut/no shut the ATM interface to get an IP again.
Does it have to be demand dial? Can't I have the router just make the connection and keep it up all the time?
10-07-2008 11:28 AM
Hello Jason,
things look like far better now
notes
a) I would move ip nat outside on dialer interface
b) to avoid DDR
try to configure the pppoe client on the pvc without the last option
c) to have the DDR to restart is just enough to make an extended ping you don't need anymore to do shut/no shut on the atm interface
Hope to help
Giuseppe
10-07-2008 12:09 PM
Made the changes and it looks like it is working. I just have to call AT&T to find out why I'm not getting the static IP that was reserved for me.
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