How to configure Gigabit Ethernet as Secondary and cellular interface as primary in Cisco ISR819 router

[Narendranadh]

When I am configuring Gigabit Ethernet port as the primary and Cellular interface as Secondary, here my network gets fluctuated when I am using network from Gigabit Ethernet and at the same time, cellular is receiving its signal. If my cellular signal was lost then the fluctuation is stopping.

So, to avoid this problem I have decided to make the cellular network as Primary and Gigabit Ethernet as Secondary. Then I can use Gigabit Ethernet when ever I don't have the cellular signal. By this way, I can stop fluctuation.

Here the question is how to change the Gigabit Ethernet as a Secondary and cellular interface as primary in Cisco ISR819 router. Please, Can any one help me in rectifying this issue?

[Hilda Arteaga]

Hi NARENDRANADH@PROINFNET.COM

Delimitating the way are going to send a traffic depends on many facts, the router, configuration, the Service Provider, set up rules, etc.

In order to provide you an accurate solution, could you please share your configuration so we can review which solution may fit this situation better?

Meanwhile, I would like to share with you some information that may be helpful.

To configure the Gigabit Ethernet port as the primary and Cellular interface as Secondary you can use “higher administrative distance”, that is: A higher administrative distance should be configured for the route through the backup interface so that it is used only when the primary interface is down.

You can find more details on this document at the “Configuring the Cellular Interface

“ part (step 10): https://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/software/feature/guide/ehwic-4g-ltesw-book.html

As for the fluctuations this seems to be caused by a network disconnect due to IP source address violations.  This behavior is resolved by reconfiguring the traffic to be tunneled, NAT, or access control lists (ACLs) so that no traffic is routed without being tunneled or subjected to NAT.

Hope this helps!