call back using modem module

[miwitte]

I am looking for a way to use the modem module in a 3845 to do call back. I will be used for a term server for DR purposes so it has to work everytime. I was thinking of using MS-CHAP to dial the modem, then use the Async interface configured with PPP, Chap and Callback to call the server back. I am having trouble binding the PPP on the Aysnc and the modem. I can connect, but it doesn't appear to kick off any PPP negotiation. Has anyone done something like this, before I put the effort into making this work? Seems feesible.

[skra]

Try the following!

http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1831/products_configuration_guide_chapter09186a008033a6c4.html

[skra]

and also the following:

http://www.cisco.com/en/US/partner/tech/tk801/tk36/technologies_configuration_example09186a008009457e.shtml

http://www.cisco.com/en/US/partner/tech/tk801/tk36/technologies_configuration_example09186a0080094338.shtml

hope it helps!

[miwitte]

I cannot open these links up even though I am logged into the Cisco site. In any case, I can negotiate the PPP connection succesfully with MS dialup using CHAP, I am now having issues with dialback. Here is the error from debug

003756: *Jan 19 17:06:43.481 UTC: %LINK-3-UPDOWN: Interface Async0/0/0, changed state to up

003757: *Jan 19 17:06:43.825 UTC: As0/0/0 MCB: Initialize

003758: *Jan 19 17:06:43.825 UTC: As0/0/0 MCB: Flush

003759: *Jan 19 17:06:43.825 UTC: As0/0/0 MCB: Start

003760: *Jan 19 17:06:43.825 UTC: As0/0/0 MCB: Callback not authorized for this user blm

003761: *Jan 19 17:06:43.825 UTC: As0/0/0 MCB: Newstate 0-INIT -> 2-WAIT_RESPONSE

003762: *Jan 19 17:06:43.825 UTC: As0/0/0 MCB: O Request Id 4 Callback Type None

003763: *Jan 19 17:06:43.965 UTC: As0/0/0 PPP: I MCB Response(2) id 4 len 6

003764: *Jan 19 17:06:43.965 UTC: As0/0/0 MCB: I 2 4 0 6 1 2

003765: *Jan 19 17:06:43.965 UTC: As0/0/0 MCB: Received response

003766: *Jan 19 17:06:43.965 UTC: As0/0/0 MCB: Response CBK-None 1 2

003767: *Jan 19 17:06:43.965 UTC: As0/0/0 MCB: O Ack Id 4 Callback Type None

003768: *Jan 19 17:06:43.965 UTC: As0/0/0 MCB: No Callback negotiated; Exit

003769: *Jan 19 17:06:43.965 UTC: As0/0/0 MCB: Flush

interface Async0/0/0

ip unnumbered GigabitEthernet0/0

no ip redirects

no ip unreachables

no ip proxy-arp

encapsulation ppp

dialer in-band

dialer enable-timeout 10

dialer map ip 10.250.41.253 name blm class blm 99990000000

dialer-group 1

async mode interactive

peer default ip address pool blm

ppp callback accept

ppp authentication chap

ppp chap hostname xxx

ppp chap password xxx

!

ip local pool blm 10.250.41.253

ip classless

!

!

ip http server

ip http authentication local

no ip http secure-server

!

!

map-class dialer blm

dialer callback-server username

logging trap debugging

dialer-list 1 protocol ip permit

[miwitte]

got it working. Had to add this so it would call back.

username xxx callback-dialstring xxxx password xxxx

Just trying to work out a default route problem. It appears that when I connect I lose connectivity because this becomes my default route. After this I need to get this workign with radius. Fun!

[kperry]

I am trying to do the same with a WIC-1AM except using "service exec-callback" which is supposed to only give a console session(no ip routing) to the router. What does your line0/0/0 config look like?

[miwitte]

This maybe a little long, but I went through a lot to get this to work the way I wanted it to. I wanted to be able to dial into the router, get authorized by radius and then local if radius was down, then get a callback to a number tied to the username/password combo(different support staffs home or work #) The key was the callback for us. The first problem was that just the modem(line 0/0/0) could not be configured for callback as you need PPP for that so I needed to use PPP CHAP under the ASYNC0/0/0 line. I finally got this working, then found that if i dialed in Hyperterm I could get right in without being called back. One final changed fixed this. I use DUN on a windows box and it works great. Just make sure that you don't accept the default route in the DUN config. once you are connceted, just telnet to the ip address on the box. Let me know if you have issues I probabaly had them all. Here is my config and notes;

#use a different one for each user with their phone #

username blm callback-dialstring xxxx password xxxx

#sets dhcp scope for DUN

ip dhcp excluded-address 10.1.41.1 10.1.41.250 ( I used the same network as my gi0/0)

!

ip dhcp pool blah

network 10.1.41.0 255.255.255.0

interface Async0/0/0

ip unnumbered GigabitEthernet0/0

no ip redirects

no ip unreachables

no ip proxy-arp

encapsulation ppp

dialer in-band

dialer callback-secure (forces redial)

dialer enable-timeout 10

dialer-group 1

async mode dedicated (only PPP or SLIP no hyperterm)

peer default ip address dhcp-pool blah

ppp max-configure 3 (disconnect faster if can't neg PPP)

ppp callback accept (accept callback)

ppp authentication chap

line 0/0/0

exec-timeout 0 0

login local

modem InOut

modem autoconfigure discovery

transport input telnet ssh

transport output telnet ssh

autoselect ppp

stopbits 1

speed 115200

flowcontrol hardware

dialer-list 1 protocol ip permit