Re: IP address used by Sockets

["Joe Wells" <jwells@xxxxxxxxx>]

I think I figured it out......I just need to use this - 

eval      sin_addr = inet_addr('aa.aa.aa.aa')  

Thanks for everyone's assistance.

Joe

Joe Wells
University of Alabama Health Services Foundation
500 22nd Street South, Suite 308
Birmingham, AL 35233
205-731-5610

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> > > On 9/30/2009 at 10:44 AM, in message <4AC33694.9C78.0031.0@xxxxxxxxx>,
Joe
Wells<jwells@xxxxxxxxx> wrote:
> Apologies in advance for what may turn into a rambling email......
>
> OK, to better explain the situation -  Our 400 has two ip addresses -
> aa.aa.aa.aa and bb.bb.bb.bbb.
>
> The server program uses bind() and specifies a local port.
> When the program is running, netstat shows the local ip as aa.aa.aa.aa .
> This works fine (at the moment).
>
> The client program specifies an ip address and port for the host.
> When first written several weeks ago, this program worked fine.
> While testing yesterday, the connection timed out.
> Netstat showed that the local ip was bb.bb.bb.bbb.  This is why it would 
> not
> connect.
> I tried again this morning and it used aa.aa.aa.aa and it ran fine.
> I will try to get the hospital network folks to open up bb.bb.bb.bbb 
> like
> aa.aa.aa.aa, but in the interim, I would like to force the client 
> program to
> use aa.aa.aa.aa as the local ip.  Let me mention that we are part of the
> university hospital system and we are communicating with an affiliated
> hospital.  The affiliated hospital is outside of the university 
> hospital's
> firewall.  So, the university hosptal network guys configured a tunnel 
> (not
> sure if this is the correct word) that only allows traffic from our ip
> address (aa.aa.aa.aa) to a specific port on the affiliated hospital's ip
> address. And likewise, only traffic from the affiliated hospital's ip
> address to a specific port on our ip address (aa.aa.aa.aa).  Hopefully 
> this
> adequately (and correctly) explains the situation.
>
> In theory, I understand what Michael is suggesting.  Unfortunately, I am 
> new
> to sockets and am struggling with how/where to specify the ip address.  
> The
> bind() that is called in the server program does not specify an ip, only 
> a
> port.
>
> Any help, tips, suggestions, or examples would be most appreciated.
>
> Thanks,
>
> Joe
>
>
>
>
>
>
> Joe Wells
> University of Alabama Health Services Foundation
> 500 22nd Street South, Suite 308
> Birmingham, AL 35233
> 205-731-5610
>
> CONFIDENTIALITY NOTICE
> This e-mail is intended for the sole use of the individual(s) to whom it 
> is
> addressed, and may contain information that is privileged, confidential 
> and
> exempt from disclosure under applicable law.  You are hereby notified 
> that
> any dissemination, duplication or distribution of this transmission by
> someone other than the intended addressee or its designated agent is
> strictly prohibited.  If you receive this e-mail in error, please notify 
> me
> immediately by replying to this e-mail.
>
> > > > On 9/29/2009 at 9:37 PM, in message
> <4AC2C45F.8040902@xxxxxxxxxxxxxxxx>,
> Scott Klement<rpg400-l@xxxxxxxxxxxxxxxx> wrote:
> > The bind() API can be used to force a TCP socket to use a particular IP 
> > address, as Michael already explained.  Set the port to 0 to let the OS 
> > choose the port.
> >
> > However, this doesn't make sense to do.  IF your TCP/IP routes are 
> > configured properly, it will automatically pick the correct IP address. 
> >   If the routes aren't configured properly, binding to a particular 
> > address won't help you, because the packets still need to be routed 
> > correctly for the connection to work.
> >
> > So this doesn't make a lot of sense to me.
> >
> > Binding to a particular IP address is a tool usually used on a listening

> > server program so that you can (for example) listen on your internal 
> > subnet without allowing access from the public internet.  Stuff like 
> > that.  It doesn't make sense to use in a client program -- at least not 
> > in my experience.
> >
> > I wonder if you don't have a misconfigured route somewhere?
> >
> >
> >
> > Joe Wells wrote:
> > > Our 400 has two IP addresses.
> > >
> > > Using Scott Klement's socket utilities service program, I have created
> > > working client and server programs.
> > >
> > > Here is my dilemma - our network folks established a secure connection
> > > (tunnel?) between us  and another system.  The problem is that the one 
> > of my
> > > socket programs is now using the "other" ip address on our 400. 
> > > Consequently, this program cannot connect!
> > >
> > > So, my question is - Is there a way to specify the outbound IP address 
> > the
> > > socket uses?
> > >
> > > Thanks,
> > >
> > > Joe
> > >
> > > Joe Wells
> > > University of Alabama Health Services Foundation
> > > 500 22nd Street South, Suite 308
> > > Birmingham, AL 35233
> > > 205-731-5610
> > >
> > > CONFIDENTIALITY NOTICE
> > > This e-mail is intended for the sole use of the individual(s) to whom
it
> > is
> > > addressed, and may contain information that is privileged, confidential

> > and
> > > exempt from disclosure under applicable law.  You are hereby notified 
> > that
> > > any dissemination, duplication or distribution of this transmission by
> > > someone other than the intended addressee or its designated agent is
> > > strictly prohibited.  If you receive this e-mail in error, please
notify
> > me
> > > immediately by replying to this e-mail.