Connecting two Cisco routers back-to-back over async (analog) dialup

[doublea1535]

Hello all,

I am having some difficulty connectin two Ciscos back-to-back using asynchronous dialup lines. The routers, modems (USR), and phone lines are known good. I can get the routers to work by dialing up to my ISP but want to connect them back-to-back. Heres the config I am using:

--------------------
Cisco 2511 (term01)
--------------------
!
interface Async16
description 5555555551
ip address 1.1.1.1 255.255.255.0
encapsulation ppp
dialer in-band
dialer map ip 1.1.1.2 5555555550
dialer-group 1
async default routing
async mode interactive
peer default ip address 1.1.1.2
ppp authentication chap
ppp chap hostname term01
ppp chap password letmein
!
ip route 1.1.1.2 255.255.255.255 Async16
access-list 100 permit ip any host 1.1.1.2
dialer-list 1 protocol ip list 100
username frsw02 password letmein
!
line 16
modem InOut
transport input all
transport output all
autoselect ppp
speed 115200
flowcontrol hardware
modem autoconfigure discovery
!
--------------------
Cisco 2523(frsw02)
--------------------
!
interface Serial3
physical-layer async
description 5555555550
ip address 1.1.1.2 255.255.255.0
encapsulation ppp
dialer in-band
dialer map ip 1.1.1.1 5555555551
dialer-group 1
async default routing
async mode interactive
peer default ip address 1.1.1.1
ppp authentication chap
ppp chap hostname frsw02
ppp chap password letmein
!
username term01 password letmein
access-list 100 permit ip any host 1.1.1.1
dialer-list 1 protocol ip list 100
ip route 1.1.1.1 255.255.255.255 Serial3
!
line 3
autoselect ppp
modem InOut
modem autoconfigure discovery
transport input all
transport output pad v120 telnet rlogin udptn
speed 115200
flowcontrol hardware
!

 

[doublea1535]

Here is the output from a debug all on frsw02
---------------------------------------------

frsw02#debug all
This may severely impact network performance. Continue? [confirm]
All possible debugging has been turned on
frsw02#ping 1.1.1.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
frsw02#
00:08:33: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial3), len 100, sending
00:08:33: Se3 DDR: ip (s=1.1.1.2, d=1.1.1.1), 100 bytes, outgoing interesting (list 100)
00:08:33: DDR: 45000064 00000000 FF01B794 01010102 01010101 08007909
00:08:33: DDR: 22030BD6 00000000 0007D760 ABCDABCD ABCDABCD ABCDABCD
00:08:33: Se3 DDR: Dialing cause ip (s=1.1.1.2, d=1.1.1.1)
00:08:33: Se3 DDR: No holdq created - not configured
00:08:33: Se3 DDR: Attempting to dial 5555555550
00:08:33: CHAT3: Attempting async line dialer script
00:08:33: CHAT3: no matching chat script found for 3033881764
00:08:33: CHAT3: Dialing using Modem script: d0efault-d0ials0cript & System script: none
00:08:33: Se3 DDR: Increment call, 0
00:08:33: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial3), len 100, encapsulation failed
00:08:33: CHAT3: process started
00:08:33: CHAT3: Asserting DTR
00:08:33: CHAT3: Chat script d0efault-d0ials0cript started
00:08:33: CHAT3: Sending string: ATZ
00:08:34: CHAT3: Expecting string: OK
00:08:34: CHAT3: Completed match for expect: OK
00:08:34: CHAT3: Sending string: AT
00:08:34: CHAT3: Expecting string: OK
00:08:34: CHAT3: Completed match for expect: OK
00:08:34: CHAT3: Sending string: ATDT\T<5555555550>
00:08:34: CHAT3: Expecting string: CONNECT
00:08:35: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial3), len 100, sending
00:08:35: Se3 DDR: ip (s=1.1.1.2, d=1.1.1.1), 100 bytes, outgoing interesting (list 100)
00:08:35: DDR: 45000064 00010000 FF01B793 01010102 01010101 08007138
00:08:35: DDR: 22040BD6 00000000 0007DF30 ABCDABCD ABCDABCD ABCDABCD
00:08:35: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial3), len 100, encapsulation failed
00:08:37: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial3), len 100, sending
00:08:37: Se3 DDR: ip (s=1.1.1.2, d=1.1.1.1), 100 bytes, outgoing interesting (list 100)
00:08:37: DDR: 45000064 00020000 FF01B792 01010102 01010101 08006967
00:08:37: DDR: 22050BD6 00000000 0007E700 ABCDABCD ABCDABCD ABCDABCD
00:08:37: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial3), len 100, encapsulation failed
00:08:39: CHAT3: Found abort string BUSY expecting CONNECT
00:08:39: CHAT3: Chat script d0efault-d0ials0cript finished, status = Connection aborted
00:08:39: Se3 AAA/DISC: 9/"NAS Error"
00:08:39: Se3 AAA/DISC/EXT: 1002/"Unknown"
00:08:39: Se3 AAA/DISC: 9/"NAS Error"
00:08:39: Se3 AAA/DISC/EXT: 1002/"Unknown"
00:08:39: TTY3: Line reset by "Async dialer"
00:08:39: Serial3: Async Interface dial-out failure
00:08:39: Se3 DDR: disconnecting call
00:08:39: Se3 BAP: Get connect id 0
00:08:39: Se3 DDR: Decrement call, 1
00:08:39: Se3 BAP: Get connect id 0
00:08:39: TTY3: Modem: (unknown)->HANGUP
00:08:39: TTY3: destroy timer type 0
00:08:39: TTY3: destroy timer type 1
00:08:39: TTY3: destroy timer type 3
00:08:39: TTY3: destroy timer type 4
00:08:39: TTY3: destroy timer type 2
00:08:39: Se3 AAA/DISC: 2/"Lost Carrier"
00:08:39: Se3 AAA/DISC/EXT: 1011/"Lost Carrier"
00:08:39: Se3 AAA/DISC: 2/"Lost Carrier"
00:08:39: Se3 AAA/DISC/EXT: 1011/"Lost Carrier"
00:08:39: TTY3: dropping DTR, hanging up
00:08:40: tty3: Modem: HANGUP->IDLE
00:08:45: TTY3: restoring DTR
00:08:46: TTY3: autoconfigure probe started
00:08:46: TTY3: Modem command: --AT&F&C1&D2S0=1H0--
00:08:46: TTY3: Modem configuration succeeded
00:08:46: TTY3: Detected modem speed 115200
00:08:46: TTY3: Done with modem configuration
frsw02#u all
All possible debugging has been turned off

 

[doublea1535]

Seeing the error "00:08:35: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial3), len 100, encapsulation failed" makes me think I am doing something wrong with regards to my PPP setup. I have tried it with and without authentication.

 

[doublea1535]

It might be worth noting the the lines dial out on both routers, but after the first ring go to what sounds like a busy signal, but the busy signal only lasts for two pulses and then dies.

 

[doublea1535]

If someone could post a known good configuration of two Ciscos back-to-back that would be awesome. I dont care about the config details, as long as I can get it to work.