sastel opened a new issue, #16504: URL: https://github.com/apache/nuttx/issues/16504
### Description @acassis I noticed recently that multicast loopback is disabled by default in NuttX. I have a pair of applications which when I run them on the same device using Linux, discover each other via multicast loopback. However when I run these applications on the same device using NuttX (kernel mode), they do not discover each other, even though applications on other devices can see their multicast traffic. In `nuttx/net/udp/udp_send.c`, you can see that there is support for `IP_MULTICAST_LOOP` in the code. I have the relevant options set in my defconfig, so if that bit is set then it should be looping back. It seems that `IP_MULTICAST_LOOP` is set by default in Linux, but in NuttX the bit is not set by default in `conn->sconn.s_options`. I have two questions based on this, and I'm hoping someone more knowledgeable than I about this stuff can help. 1. Why doesn't NuttX set this bit by default? 2. Should NuttX set this bit by default? I can use the sockets API to set this in my communications stack, but it isn't clear to me what is the right place to do it. ### Verification - [x] I have verified before submitting the report. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@nuttx.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
