Working with loopback (127.0.0.1)

[kolban]

I am working with some open source code that is making use of the loopback interface ... IP address 127.0.0.1. I ran into a problem and created an issue here:

https://github.com/espressif/esp-idf/issues/114

To which a fellow community member came back and pointed the issue at the notion of the LWIP and Loopback enablement. This opened up a whole question area ...

Q: Is loopback processing supported with an ESP32? For example, can I make a network connection from my ESP32 to a socket endpoint that is ALSO on the same ESP32 at address 127.0.0.1?

Q: If loopback processing is supported, is it enabled by default? We seem to be finding traces to discussion on having to set flags at LWIP compile time. See: http://www.nongnu.org/lwip/2_0_0/group_ ... _loop.html

Q: ... and finally ... if loopback processing is supported but not enabled by default, do we have a recipe to actually enable it?

[ESP_igrr]

We have a patch for loopback support sitting in mDNS support branch. I'll see if we can separate it and merge into master.

[WiFive]

We have a patch for loopback support sitting in mDNS support branch. I'll see if we can separate it and merge into master.

mDNS sounds good, and throw in uPnP and NBNS while you're at it