From: Daemon Le <dle@...>
Date: 2004-05-22T11:43:48+09:00
Subject: Re: Multicasting with Ruby?

As Dan had stated, I chose the multicast address arbitrarily.  Up to you 
which one you decide to use.  But do check the RFC.

I'm not sure why you are getting the error either.  But just for your own 
info, I'm using Ruby v1.6.8 (manually compiled but default options) on 
Redhat 7.3.  I believe they're standard, but I've also verified IPPROTO_IP 
and IP_ADD_MEMBERSHIP numbers are defined in the include files (on my box, 
/usr/include/linux/in.h, /usr/include/netinet/in.h for IPPROTO..., and 
usr/include/linux/in.h, /usr/include/bits/in.h for IP_ADD...).

It is also true that the kernel must be compiled with 
"CONFIG_IP_MULTICAST=y".  But I believe this is also pretty normal for 
Redhat distributed kernels.

Good luck to you.  I'm learning myself.


- Daemon


James Britt <jamesUNDERBARb@neurogami.com> wrote in
news:40AE24F3.9020006@neurogami.com: 

> Pardon my networking ignorance, but in this example, where does the 
> address 228.5.6.8 come from?  Or does it matter much?
> 
> I'm trying learn more about multicasting, but when I run the example
> on my Red Hat box I get
> 
>    mcast.rb:13:in `setsockopt': No such device (Errno::ENODEV)
> 
> where line 13 is
>   sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP, mreq)
> 
> ruby -v gives:
>    ruby 1.8.1 (2003-12-25) [i586-linux]
> 
> 
> Thanks,
> 
> 
> James
> 
> 
>