IPv4 unicast sendto() through a network interface

Dear all

How can I send a unicast packet through a particular network interface
of my machine using UDP sendto() function in C? How can I send
multicast sendto() through a network interface other than by
specifying an IP like in setsockopt-MULTICST_IF( b specifying the
interface index/name). I am working on IPv4 sockets.

Thanks for all expert advices

Vinod Kumar P

Vinod Kumar P wrote:

> Dear all
>
> How can I send a unicast packet through a particular network interface
> of my machine using UDP sendto() function in C?

Bind to a specific IP address instead of INADDR_ANY.

> How can I send
> multicast sendto() through a network interface other than by
> specifying an IP like in setsockopt-MULTICST_IF( b specifying the
> interface index/name). I am working on IPv4 sockets.

You cannot do it any other way.

> Thanks for all expert advices
>
> Vinod Kumar P

--
Phil Frisbie, Jr.
Hawk Software
http://www.hawksoft.com

"Phil Frisbie, Jr." <(E-Mail Removed)> wrote in message news:<YrSnb.1308$(E-Mail Removed)>...
> Vinod Kumar P wrote:
>
> > Dear all
> >
> > How can I send a unicast packet through a particular network interface
> > of my machine using UDP sendto() function in C?
>
> Bind to a specific IP address instead of INADDR_ANY.

I tried this. But the result is negative. The packet channels through
both network interfaces. I am working on RedHat Linux Version 7.2 with
packages gcc version 2.96, glibc2.2.4-13 and glibc-devel-2.2.4-13. do
you have any idea why this happens?

>
> > How can I send
> > multicast sendto() through a network interface other than by
> > specifying an IP like in setsockopt-MULTICST_IF( b specifying the
> > interface index/name). I am working on IPv4 sockets.
>
> You cannot do it any other way.
>
> > Thanks for all expert advices
> >
> > Vinod Kumar P