# Multicast join failure and socket error 59(0x3B) **URL:** \ **Category:** NET+OS\ **Created:** [July 5, 2006, 3:41pm UTC](https://forums.digi.com/t/multicast-join-failure-and-socket-error-59-0x3b/5329 "2006-07-05T15:41:46Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![Cassius](https://avatars.discourse-cdn.com/v4/letter/c/46a35a/32.png) [@Cassius](https://forums.digi.com/u/Cassius)\ **Post date:** [July 5, 2006, 3:41pm UTC](https://forums.digi.com/t/multicast-join-failure-and-socket-error-59-0x3b/5329/1 "2006-07-05T15:41:46Z")
Multicast join failure and socket error 59(0x3B) Hi, I need to join 19 (or more) multicast groups, from 239.0.0.0 to 239.0.0.18, on one socket. After 10 well succeed join operations, setsockopt start to return errors. See the small extract of the log: 11:54:28.059 Multicast Test: Multicast (itf 0)address 239.0.0.10 add operation fails. 010.000.000.231:01540 224.000.000.050:07580 11:54:28.061 Multicast Test: socket error 59 010.000.000.231:01540 224.000.000.050:07580 11:54:29.070 Multicast Test: Multicast (itf 0)address 239.0.0.11 add operation fails. 010.000.000.231:01540 224.000.000.050:07580 … and so on. I would expect join all groups, once the driver have room to 20 for M.A.Cs, determined by MAX\_MCA (on eth\_mcast.c). Some debug information: 1-) The eth\_add\_multicast never returns an error. Also, it is never called when setsockopt have IP\_ADD\_MEMBERSHIP option. 2-) The socket error for the multicast join error is 59, and there is no documentation (or I was unable to find it) on Net+OS API Reference (file ApiReference.chm). 3-) eth\_del\_multicast is called only once. Additional information: NETOS version 60 (lib, without sources) NET+50 chip, on custom board code\_extract.c with test functions and log.txt with complete log. Some one knows what is the reason? There is another documented (or not :-)) limit that I should had observed? In this case, There is a way to expand it? Thanks,