# Why is local\_conf.json needed? **URL:** \ **Category:** Gateways\ **Created:** [May 16, 2017, 1:03pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300 "2017-05-16T13:03:25Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![marcelstoer](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/marcelstoer/32/47156_2.png) [@marcelstoer](https://www.thethingsnetwork.org/forum/u/marcelstoer)\ **Post date:** [May 16, 2017, 1:03pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/1 "2017-05-16T13:03:25Z")
Why do I need all the information in [`local_conf.json`](https://github.com/TheThingsNetwork/packet_forwarder/tree/legacy/poly_pkt_fwd) when most of those values are set (again) when the gateway is registered on [TTN.org](http://TTN.org)? Put differently, what happens if the values in `local_conf.json` diverge from those configured on [TTN.org](http://TTN.org)? ---
**Author:** ![kersing](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kersing/32/44777_2.png) [@kersing](https://www.thethingsnetwork.org/forum/u/kersing)\ **Post date:** [May 16, 2017, 10:32pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/2 "2017-05-16T22:32:09Z")
The poly forwarder uses the values in the local\_conf.json. It knows nothing about the values set in the TTN console and has no logic to access them. ---
**Author:** ![marcelstoer](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/marcelstoer/32/47156_2.png) [@marcelstoer](https://www.thethingsnetwork.org/forum/u/marcelstoer)\ **Post date:** [May 17, 2017, 5:41am UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/3 "2017-05-17T05:41:53Z")
Thanks, I know that. I’m interested in learning about the consequences of that fact. What about the other way round? Why can’t the TTN backend access and process those values rather than asking me to define them in the console? > [@marcelstoer](#): > > what happens if the values in `local_conf.json` diverge from those configured on [TTN.org](http://TTN.org)? Can I conclude then that this is not a problem? Which values in `local_conf.json` are actually required for a TTN gateway? Would it be enough to just set `gateway_ID` and a single entry for `servers` (e.g. `router.eu.thethings.network`)? Would it be correct to say that all other values (lat/long, altitude, email, etc.) _may_ be used if you were to connect the gateway to a non-TTN backend? ---
**Author:** ![kersing](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kersing/32/44777_2.png) [@kersing](https://www.thethingsnetwork.org/forum/u/kersing)\ **Post date:** [May 17, 2017, 6:14am UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/4 "2017-05-17T06:14:42Z")
The TTN backend does not have access to the settings on the gateway. The protocol used on most gateways at the moment to exchange information from the gateway to the backend is generic and does not support those TTN specifics. Both I and TTN have been working on new software that does read the settings from the console and uses them to configure the gateway. The TTN software is currently being tested, my software has been released. (installer for MultiTech and [resin.io](http://resin.io) image for Raspberry Pi) > [@marcelstoer](#): > > Can I conclude then that this is not a problem? Yes. > [@marcelstoer](#): > > Which values in local\_conf.json are actually required for a TTN gateway? Minimal settings are gateway\_id and server. Everything else is not required for TTN, other back-ends may have different requirements (most other providers use their own packet forwarder so configuration might be totally different) ---
**Author:** ![redarmee](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/redarmee/32/20484_2.png) [@redarmee](https://www.thethingsnetwork.org/forum/u/redarmee)\ **Post date:** [April 13, 2019, 7:05pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/5 "2019-04-13T19:05:50Z")
hello i used the Packet forwarder available in the link below. [[https://github.com/Lora-net/picoGW\_packet\_forwarder](https://github.com/Lora-net/picoGW_packet_forwarder)] there i found only the global\_conf but not the local\_conf. i don’t whether or not local\_conf is important. I think the local contain only the gateway\_eui and This eui can be found in global\_conf. so my qustion is that why is that local\_conf needed? does the Gateway work if we don’t put the local\_conf? please explain in simpler words. ![Capture](https://www.thethingsnetwork.org/forum/uploads/default/original/3X/a/4/a47b778f1999e3fe24801f330a3e8bd3d059666e.png) what do you mean by poly forwarder and what does it do? thankyou in advance. ---
**Author:** ![marcelstoer](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/marcelstoer/32/47156_2.png) [@marcelstoer](https://www.thethingsnetwork.org/forum/u/marcelstoer)\ **Post date:** [April 13, 2019, 7:39pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/6 "2019-04-13T19:39:23Z")
The “poly forwarder” is the legacy packet forwarder from [https://github.com/TheThingsNetwork/packet\_forwarder/tree/legacy/poly\_pkt\_fwd](https://github.com/TheThingsNetwork/packet_forwarder/tree/legacy/poly_pkt_fwd). ---
**Author:** ![kersing](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kersing/32/44777_2.png) [@kersing](https://www.thethingsnetwork.org/forum/u/kersing)\ **Post date:** [April 13, 2019, 7:39pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/7 "2019-04-13T19:39:30Z")
The intention is that you download the global\_conf.json from TTN and do not not change it. Any configuration parameters you need to set should go into local\_conf.json (that includes the gateway eui) However, modifying global\_conf.json will work as well. If your hardware works with the packet forwarder you mention you can ignore poly forwarder as it will not work with your hardware. ---
**Author:** ![TonySmith](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/tonysmith/32/46334_2.png) [@TonySmith](https://www.thethingsnetwork.org/forum/u/TonySmith)\ **Post date:** [April 13, 2019, 8:30pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/8 "2019-04-13T20:30:00Z")
> [@kersing](#): > > Both I and TTN have been working on new software that does read the settings from the console and uses them to configure the gateway. @kersing. Sounds like a great idea. Is this part of the new Semtech “Basic Station” version of the packet forwarder combined with the TTN V3 Server or is this something quite separate? @redarmee For a deep dive on the contents on local\_conf and global\_conf have a look at this tutorial. [https://www.youtube.com/watch?v=WaWca5QfFp0](https://www.youtube.com/watch?v=WaWca5QfFp0) ---
**Author:** ![kersing](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kersing/32/44777_2.png) [@kersing](https://www.thethingsnetwork.org/forum/u/kersing)\ **Post date:** [April 13, 2019, 9:12pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/9 "2019-04-13T21:12:08Z")
To all: This is a 2 year old discussion. Technology changed since then with for instance the release of Basic Station by Semtech and the upcoming implementation (no I don’t know the timeline) of TTN V3. To avoid further confusion I’m going to close this thread. @TonySmith: My crystal ball did not show Basic Station software two years ago. Not related. ---
**Author:** ![kersing](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/kersing/32/44777_2.png) [@kersing](https://www.thethingsnetwork.org/forum/u/kersing)\ **Post date:** [April 13, 2019, 9:12pm UTC](https://www.thethingsnetwork.org/forum/t/why-is-local-conf-json-needed/7300/10 "2019-04-13T21:12:19Z")