Description

I configured an SRX345 cluster, in which I inserted 1 module "LTE Mini Physical Interface Modules (LTE Mini-PIM)" on each node.

I followed the procedure for LTE Mini-PIM in a High Availability Cluster Mode from the link below:

https://www.juniper.net/documentation/us/en/software/junos/interfaces-security-devices/topics/topic-map/lte-mini-pim-topicmap.html#d92e164

 

We performed the following switching tests: -

1). Restart for the node with the modem up - OK switches in 4 minutes

2). Turn off the main cellular interface with disable - ok switches in 10 seconds

3). Disconnection from the network for one of the SIMs with APN change in the config. - NOK no longer switches, both cellular interfaces remain down.

 

Please help us with this situation where failover/switching did not happen and help us in fixing the issue.

 

Symptoms

admin> show configuration interfaces cl-1/0/0

dialer-options {

   pool 1 priority 100;

}

act-sim 1;

cellular-options {

   sim 1 {

       select-profile profile-id 1;

       radio-access automatic;

   }

}

 

{primary:node0}

admin> show configuration interfaces cl-6/0/0   

dialer-options {

   pool 1 priority 1;

}

act-sim 1;

cellular-options {

   sim 1 {

       select-profile profile-id 1;

       radio-access automatic;

   }

}

 

admin> show configuration interfaces dl0

unit 0 {

   family inet {

       negotiate-address;

   }

   family inet6;

   dialer-options {

       pool 1;

       dial-string 1;

       redial-delay 10;

       route x.x.x.x/32;

       always-on;

 

 

admin> show modem wireless profiles cl-1/0/0 slot 1

Profile details

 Max profiles: 16

 Default profile Id: 1

 

Profile 1: ACTIVE

 Valid: TRUE

 Access point name (APN): topex

 Authentication: None

 IP Version: IPV4V6

Profile 2: Invalid

Profile 3: Invalid

……….

{primary:node0}

admin@> show modem wireless profiles cl-6/0/0 slot 1   

Profile details

 Max profiles: 16

 Default profile Id: 1

 

Profile 1: ACTIVE

 Valid: TRUE

 Access point name (APN): topex

 Authentication: None

 IP Version: IPV4V6

Profile 2: Inactive

 Valid: TRUE

 Access point name (APN): topex

 Authentication: None

 IP Version: IPV4V6

Profile 3: Invalid

…………

 

admin> show interfaces terse | match dl0

dl0                    up   up

dl0.0                  up   up  inet    y.y.y.y/30

 

{primary:node0}

admin> show interfaces terse | match cl-   

cl-1/0/0               down down

cl-1/0/0.0             up   down

cl-6/0/0               up   up

cl-6/0/0.0             up   up

 

Currently it is active on node 1.

After this we change the APN for cl-6/0/0 to something else and then the interface goes down and Failover/Switch to the other CL interface.

 

admin> show modem wireless profiles cl-6/0/0 slot 1                                                  

Profile details

 Max profiles: 16

 Default profile Id: 1

 

Profile 1: ACTIVE

 Valid: TRUE

 Access point name (APN): BLABLA

 Authentication: None

 IP Version: IPV4V6

Profile 2: Inactive

 Valid: TRUE

 Access point name (APN): topex

 Authentication: None

 IP Version: IPV4V6

Profile 3: Invalid

Profile 4: Invalid

Profile 5: Invalid

 

 

admin> show modem wireless profiles cl-1/0/0 slot 1                                                  

Profile details

 Max profiles: 16

 Default profile Id: 1

 

Profile 1: ACTIVE

 Valid: TRUE

 Access point name (APN): topex

 Authentication: None

 IP Version: IPV4V6

Profile 2: Invalid

Profile 3: Invalid

 

 

And when we check the interface status, Cl interface remains down on both the interface and also dl interface does not have any IP assigned to it.

 

admin> show interfaces terse | match cl-                                                             

cl-1/0/0               down down

cl-1/0/0.0             up   down

cl-6/0/0               down down

cl-6/0/0.0             up   down

 

{primary:node0}

admin>

 

{primary:node0}

admin> show interfaces terse | match dl0   

dl0                    up   up

dl0.0                  up   up  inet 

 

The only way to failover the traffic is by disabling the interface where we changed the APN name and after few seconds or max a minute the other cl interface comes up and dl interface gets an ip as well..

 

admin# set interfaces cl-6/0/0 disable

 

admin> show interfaces terse | match cl-   

cl-1/0/0               up   up

cl-1/0/0.0             up   up 

cl-6/0/0               down down

cl-6/0/0.0             up   down

 

{primary:node0}

admin> show interfaces terse | match dl0   

dl0                    up   up

dl0.0                  up   up  inet    a.b.c.d/30

 

Solution

After having an extensive troubleshooting, we found that we need to have one more command for this is to work properly.

set interface dl0 unit 0 dialer-options self-recover-time 15

 

Once we added this above line, failover started to work fine.

 

 

 

Modification History

2023-11-20 : Updated KB