# Running MapProfileOnNetworkInterface is faulting **URL:** \ **Category:** Legato Application Framework\ **Created:** [February 13, 2018, 7:58pm UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089 "2018-02-13T19:58:49Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![EvetsMostel](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@EvetsMostel](https://forum.legato.io/u/EvetsMostel)\ **Post date:** [February 13, 2018, 7:58pm UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089/1 "2018-02-13T19:58:49Z")
Hi, I’m receiving an **LE\_FAULT** when I try to use **le\_mdc\_MapProfileOnNetworkInterface** with a valide profile and network interface string name (“ecm0”). Can you tell me how this is supposed to be used? The documentation doesn’t really specify. This is running R7 for a WP7601 Thanks! ---
**Author:** ![lotam](https://avatars.discourse-cdn.com/v4/letter/l/958977/32.png) [@lotam](https://forum.legato.io/u/lotam)\ **Post date:** [February 14, 2018, 12:59am UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089/2 "2018-02-14T00:59:24Z")
This API used to map profile to data session network interface, rmnet type, like the one enabled with “cm data connect”. ---
**Author:** ![EvetsMostel](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@EvetsMostel](https://forum.legato.io/u/EvetsMostel)\ **Post date:** [February 14, 2018, 1:56pm UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089/3 "2018-02-14T13:56:38Z")
@lotam, thanks for replying. I know, that’s what the docs say… But to me this implies that it is creating a route for whenever that profile is active. However, like I said, I just get a fault returned. I’ve tried a new interface and existing interfaces, and nothing happens. The docs say it basically allows you to create more separate data connections. But if I can’t pick the network I want, then what good is it? ---
**Author:** ![riotc](https://avatars.discourse-cdn.com/v4/letter/r/65b543/32.png) [@riotc](https://forum.legato.io/u/riotc)\ **Post date:** [October 16, 2018, 7:52am UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089/4 "2018-10-16T07:52:59Z")
Hello @EvetsMostel, Can you post the logs (with log level DEBUG) in case you are still facing the issue? Have you also tried using this API with the new releases? ---
**Author:** ![EvetsMostel](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@EvetsMostel](https://forum.legato.io/u/EvetsMostel)\ **Post date:** [October 16, 2018, 12:40pm UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089/5 "2018-10-16T12:40:22Z")
Hi @riotc, I’ve worked around it. But the question still remains… What exactly is the effect of using it assuming it is working, and how is it supposed to be used? Thanks! ---
**Author:** ![riotc](https://avatars.discourse-cdn.com/v4/letter/r/65b543/32.png) [@riotc](https://forum.legato.io/u/riotc)\ **Post date:** [October 17, 2018, 9:15am UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089/6 "2018-10-17T09:15:37Z")
Hello @EvetsMostel, The le\_mdc\_MapProfileOnNetworkInterface API is used to map a specific PDP profile to a specific data session interface. For example, If there are two different applications with PDP contexts with different profiles, say PDP1 and PDP2 can be mapped to the interfaces rmnet\_data0 and rmnet\_data1. This API is associating a profile to a network interface here. Regarding the usage of this API- You can refer to an example provided in _legato-a.b.c/apps/test/modemServices/mdc/mdcIntegrationTest._ Thanks ---
**Author:** ![EvetsMostel](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@EvetsMostel](https://forum.legato.io/u/EvetsMostel)\ **Post date:** [October 17, 2018, 3:29pm UTC](https://forum.legato.io/t/running-mapprofileonnetworkinterface-is-faulting/3089/7 "2018-10-17T15:29:10Z")
Hi @riotc, That’s what I thought. Thanks for the information! Evets