Very Computer

by **Ric** » Mon, 24 Mar 2003 08:35:45

Can somone point me to an RFC or some doc to help me determine if the
behavior I describe below is a feature of Linux or a bug?

I have a reproduceable test case where I have a client that subscribes
to a mutlicast address and port, say 239.68.1.1 port 7777.

My understanding is that it would only receive mutlicast messages to
that specific port AND address. (As it is with Solaris 8.)

What I'm seeing is that if on a client, I am subscribing to
239.68.1.1:7777 and 239.68.2.2.7777, that the application (a basic C
program that subscribes to the address and port) receives all
mutlicast traffic destined to that port regardless of address. This
has been reproduced in both RedHat AS2.1 and RedHat 8.0 with the
latest kernels as of this post.

Basicly, it looks like Linux seems to satisfy a subscription request
based on the port alone.

Thanks,
--Rick

by **Ric** » Wed, 26 Mar 2003 01:14:14

Nevermind, my stupid mistake. The address was INADDR_ANY.

--Rick

> Can somone point me to an RFC or some doc to help me determine if the
> behavior I describe below is a feature of Linux or a bug?

> I have a reproduceable test case where I have a client that subscribes
> to a mutlicast address and port, say 239.68.1.1 port 7777.

> My understanding is that it would only receive mutlicast messages to
> that specific port AND address. (As it is with Solaris 8.)

> What I'm seeing is that if on a client, I am subscribing to
> 239.68.1.1:7777 and 239.68.2.2.7777, that the application (a basic C
> program that subscribes to the address and port) receives all
> mutlicast traffic destined to that port regardless of address. This
> has been reproduced in both RedHat AS2.1 and RedHat 8.0 with the
> latest kernels as of this post.

> Basicly, it looks like Linux seems to satisfy a subscription request
> based on the port alone.

> Thanks,
> --Rick

Very Computer

Linux Multicast bug or feature??

Linux Multicast bug or feature??

Linux Multicast bug or feature??