Question

Continuing the list of issues with the RUT955 failover:

Failover is switching to wrong interface first. Should be mob1s1a1, but is switching to mob1s2a1 for some reason.

relevant /etc/config/network:

config interface 'mob1s2a1'

option proto 'wwan'

option modem '1-1.4'

option sim '2'

option pdp '1'

option dhcpv6 '0'

option force_link '0'

option method 'nat'

option pdptype 'ip'

option stp '0'

option igmp_snooping '0'

option disabled '0'

option apn 'internet'

option auth 'none'

option metric '3'

config interface 'mob1s1a1'

option proto 'wwan'

option modem '1-1.4'

option sim '1'

option pdp '1'

option dhcpv6 '0'

option apn 'vodafone'

option auth 'none'

option disabled '0'

option metric '2'

Answer 1

Hello,

Have you using latest firmware and have you recently updated router's firmware with Keep settings option set to on?

Could you try to reset the router to factory defaults?

I would like to know some more details regarding your configuration:

Do you have SIM switch enabled?

Is the first SIM configured as a primary SIM in Network -> Mobile section?

Best regards,

Comments

Hello, thankyou

I have recently updated the firmware with keep settings enabled (this fixed a separate, catastrophic modem error).

I can reset the modem when I am onsite, but until then I have to troubleshoot remotely.

I do have SIM switch enabled.

The second SIM was enabled as Default in Network>Mobile.

Just now I clicked SAVE and APPLY for Failover, and then the failover started using the correct SIM. (I did not change any settings for some days).

Can you explain how interface order, and "Default SIM" settings operate in heirarchy? They seem like conflicting settings.

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Since the device is capable of having several WAN interfaces online at the same time, including wired WAN, mobile and WiFi WAN, the order of those interfaces defines, which will be used as the main interface to route traffic to the internet. In failover configuration, this is defined by the metric value. The lower the metric, the higher the priority of the interface. Now in terms of the mobile connectivity, even if the device has two SIM slots, there is only a single modem, meaning that only one SIM is operational at the time. If SIM switch is configured, it creates parallel subroutine, which checks current SIM data connection health. However, it does not override failover interfaces priorities, unless interfaces for SIM1 and SIM 2 are configured in different order relative to other WAN interfaces.