Cisco 8200L with cellular modem configuration

[nagelj]

I inherited a network with a Cisco 8200L with a P-LTEA-EA Module and a Sierra Wireless EM7455 cellular modem.  I am new to LTE/cellular configuration on Cisco routers.  I am told how this configuration is supposed to work is that you send an SMS message to a phone number which will bring up the cellular link for 2 minutes and then shutdown unless there is SSH traffic.  You are then supposed to be able to SSH to the cellular interface of the router.  This is no longer working.  I am told that the previous engineer upgraded the code of the router and then it broke.  I did try downgrading to the code  version that the router was previously running but that did not fix the issue.  

If I do a cellular 0/2/0 lte sms view summ I do see the messages getting to the router.  The cellular interface does show as up but it does not have an IP address.  I did work with Cisco TAC a bit and they had me create dialer watch-list 2 and apply it under the Cellular 0/2/0 interface.  When I do this the Cellular interface does obtain an IP address but I am unable to ping or SSH to the IP.

I have pasted some of the cellular configuration below.

Any thoughts or ideas on how to get this working would be appreciated.

Cellular0/2/0 is up (spoofing), line protocol is up (spoofing)
Hardware is LTE Advanced pluggable - Europe/North America Multimode LTE/DC-HSPA+/HSPA+/HSPA
Internet address will be negotiated using IPCP

controller Cellular 0/2/0
lte sim data-profile 2 attach-profile 2 slot 0
!

interface Cellular0/2/0
ip address negotiated
ip tcp adjust-mss 1390
dialer in-band
dialer idle-timeout 0
pulse-time 1
!
interface Cellular0/2/1
no ip address
!

interface Dialer1
ip address negotiated
dialer in-band
dialer idle-timeout 120 inbound
dialer caller 12345678989 callback
dialer watch-group 1
!

ip access-list extended 100
10 permit tcp any any eq 22

!

dialer watch-list 1 ip 1.2.3.4 255.255.255.255
dialer watch-list 1 delay route-check initial 60
dialer watch-list 1 delay connect 1
dialer watch-list 2 ip 5.6.7.8 255.255.255.255
dialer watch-list 2 delay route-check initial 60
dialer watch-list 2 delay connect 1
!
dialer clid group test
number 12345678989

dialer-list 1 protocol ip permit
!
!
!
line con 0
login local
stopbits 1
line aux 0
line 0/1/0 0/1/15
exec-timeout 0 0
no exec
transport input telnet
transport output all
line vty 0 4
privilege level 15
login local
transport input ssh
transport output all
line vty 5 14
privilege level 15
login local
transport input ssh
transport output all

[marce1000]

 - Have a look at https://www.cisco.com/c/en/us/td/docs/routers/iot-antennas/cellular-pluggable-modules/b-cellular-pluggable-interface-module-configuration-guide/m-cellular-serviceability.html
    that is configure logging accordingly and examine resulting logs ,

 M.

[liviu.gheorghe]

I see some things that are missing from your configuration like dialer pool-member 1 on your interface Cellular0/2/0 which is needed to reference the external Dialer 1 interface.

Also there is no chat script defined in your config and attached to the async line of the LTE modem:

Router(config)#chat-script lte "" "AT!CALL" TIMEOUT 20 "OK" 

line 3

script dialer lte

modem InOut

HTH

[nagelj]

I did some further troubleshooting and discovered that there was no route to the cellular interface.  The only route was a static default route to the inside interface to access the router from the internal network.  I added a static route to my home public IP address that used the Cellular 0/2/0 interface and then I was able to ping the cellular modem from home as well as SSH to it.  I am wondering what the best routing configuration would be to allow me to access the router from my internal network as well as from the outside through the cellular interface.   

[liviu.gheorghe]

The only problem here is knowing IP address your cellular router got from the GSM provider. I am almost sure that your IP address changes with each connection and you need some form of DNS mapping to a host name which is yours (the customer). In this case, you don't care about the IP address you received from the GSM provider because you have the hostname which the provider updates every time you connect.

I've seen such a scenario work with a service provider.

HTH