Why Cisco 1941 cellular modem not accept "encap ppp" CLI

Publié le 07/01/2014 à 09:38 par cisco2960switch Tags : blog mode you chat

I am trying to configure a new Cisco 1941 router to replace my existing 1841.

The 1841 had a GSM card in it, and the 1941 does as well, as a dial backup for the primary serial connection.

 

The original 1841 has the following configuration:

interface Cellular0/1/0

 no ip address

 ip nat outside

 ip virtual-reassembly

 encapsulation ppp

 dialer in-band

 dialer pool-member 1

 dialer-group 1

 async mode interactive

 crypto map CRYPTO_MAP_Di1

 

The current configuration for the 1941 is:

interface Cellular0/1/0

 no ip address

 ip nat outside

 ip virtual-reassembly

 encapsulation ppp

 dialer in-band

 dialer pool-member 1

 async mode interactive

 crypto map CRYPTO_MAP_Di1

 

I am trying to get the 1941 to be configured exactly the same way, however, when I try to change the configuration from "encapsulation slip" to "encapsulation ppp", I get the following error:

Cellular0/1/0: Only SLIP encapsulation supported

Also, note that the original 1841 configuration has the line "dial-group 1", but I get an error on that CLI also of the following, when trying to add that line command.

%Remove Dialer Profile Configuration first

Does anyone have any idea why I cannot change the encapsulation from slip to ppp, and why I get that error trying to issue the dialer-group command?

 

The new GSM modem does NOT support PPP at all under the newer IOS 15.x, and in addition to that, I have to also change the chat-script to the new AT commands, because ATDT no longer works either.

What about the issue with the dialer-group 1 CLI is was having an issue with?

 

The solution:

I think the issue with the dialer commands is because you have some dialer config on the interface already.  Try removing the following from the Cellular interface...

dialer in-band

dialer pool-member 1

...then try applying the dialer-group command again.

This solution also can be used for the Cisco 2951 router.

More information, please visit:http://www.3anetwork.com/blog