Arduino IDE - LwIP variants - where is the documentation?

Projects Networking, Protocols, and Devices
1

This is a question about the LwIP variants that are available in the Arduino IDE "tools" section for the ESP8266 (I'm using Adafruit's Huzzah).

Using Wireshark, I found that "V2 low memory" makes the device send 536 byte packets and "V2 higher bandwidth" makes the device send 1460 byte packets. (The latter seems to give my web server a snappier response, as one might expect.)

But it is not obvious what the differences are between the three available "higher bandwidth" options:

  • V2 higher bandwidth
  • V2 higher bandwidth no features
  • V1.4 higher bandwidth
    What are "features"? And what are the differences between V2 and V1.4?

I have not been able to find answers to that in ESP8266 Read the Docs, the ESP8266 or Arduino forums, the ESP8266 github site, the Arduino "help" system, or....anywhere on the web.

Can someone please describe (or point me to a source that describes) the differences between all of the available LwIP variants for the ESP8266?

PS: I asked this question on the esp8266 forum a month ago and got no response.

PPS: Would arduino.stackexchange be a better place to post the question? Or a different part of this Arduino forum?

Annotation 2020-05-13 093845.jpg
Annotation 2020-05-13 093845.jpg600×666 114 KB

Annotation 2020-05-13 093845.jpg
Annotation 2020-05-13 093845.jpg600×666 114 KB

2

2 and 1.4 are LWIP library versions

generic.menu.ip.lm2f.build.lwip_include=lwip2/include
generic.menu.ip.lm2f.build.lwip_lib=-llwip2-536-feat
generic.menu.ip.lm2f.build.lwip_flags=-DLWIP_OPEN_SRC -DTCP_MSS=536 -DLWIP_FEATURES=1 -DLWIP_IPV6=0
generic.menu.ip.hb2f=v2 Higher Bandwidth
generic.menu.ip.hb2f.build.lwip_include=lwip2/include
generic.menu.ip.hb2f.build.lwip_lib=-llwip2-1460-feat
generic.menu.ip.hb2f.build.lwip_flags=-DLWIP_OPEN_SRC -DTCP_MSS=1460 -DLWIP_FEATURES=1 -DLWIP_IPV6=0
generic.menu.ip.lm2n=v2 Lower Memory (no features)
generic.menu.ip.lm2n.build.lwip_include=lwip2/include
generic.menu.ip.lm2n.build.lwip_lib=-llwip2-536
generic.menu.ip.lm2n.build.lwip_flags=-DLWIP_OPEN_SRC -DTCP_MSS=536 -DLWIP_FEATURES=0 -DLWIP_IPV6=0
generic.menu.ip.hb2n=v2 Higher Bandwidth (no features)
generic.menu.ip.hb2n.build.lwip_include=lwip2/include
generic.menu.ip.hb2n.build.lwip_lib=-llwip2-1460
generic.menu.ip.hb2n.build.lwip_flags=-DLWIP_OPEN_SRC -DTCP_MSS=1460 -DLWIP_FEATURES=0 -DLWIP_IPV6=0
generic.menu.ip.lm6f=v2 IPv6 Lower Memory
generic.menu.ip.lm6f.build.lwip_include=lwip2/include
generic.menu.ip.lm6f.build.lwip_lib=-llwip6-536-feat
generic.menu.ip.lm6f.build.lwip_flags=-DLWIP_OPEN_SRC -DTCP_MSS=536 -DLWIP_FEATURES=1 -DLWIP_IPV6=1
generic.menu.ip.hb6f=v2 IPv6 Higher Bandwidth
generic.menu.ip.hb6f.build.lwip_include=lwip2/include
generic.menu.ip.hb6f.build.lwip_lib=-llwip6-1460-feat
generic.menu.ip.hb6f.build.lwip_flags=-DLWIP_OPEN_SRC -DTCP_MSS=1460 -DLWIP_FEATURES=1 -DLWIP_IPV6=1
generic.menu.ip.hb1=v1.4 Higher Bandwidth
generic.menu.ip.hb1.build.lwip_lib=-llwip_gcc
generic.menu.ip.hb1.build.lwip_flags=-DLWIP_OPEN_SRC
generic.menu.ip.src=v1.4 Compile from source
generic.menu.ip.src.build.lwip_lib=-llwip_src
generic.menu.ip.src.build.lwip_flags=-DLWIP_OPEN_SRC

3

Thank you. That confirms my packet size finding, and yes, it seemed clear that v2.0 was an update of v1.4, but I had previously looked at the LwIP github site (and elsewhere) but didn't find anything that would easily help a person decide which variant to use. E.g., why use v1.4 vs v2.0, or features/no-features? For the latter, I'll search the git site again, now with DLWIP_FEATURES as the keyword.

4

Just to make sure it's clear: the Tools > lwIP menu is a custom board option menu created by the 3rd party ESP8266 core for Arduino platform. The Arduino IDE allows platform authors to add arbitrary menus to the Tools menu. So you won't find information about specific 3rd party custom board option menu anywhere in the official Arduino documentation.

5

Thank you for the follow-up, @pert.