Hi everyone,

I am setting up a point to point connection between a PC and an
Ethernet PHY chip interfaced with a MAC layer on an FPGA. I am giving
my PC a static IP and using a UDP tester to send packets, however I
can only receive packets (on the FPGA side) if I broadcast the IP
address. When I try to send a specific IP address to the FPGA,
nothing is transmitted, ethereal doesn't even sniff it. So I'm
guessing I need to do something on the PC side, so it knows that there
is a valid IP address associated with the FPGA...How would I go about
doing this?

Thanks!

-Matt

On 20 Apr 2007, meo2662@gmail.com wrote:

> I am setting up a point to point connection between a PC and an
> Ethernet PHY chip interfaced with a MAC layer on an FPGA. I am
> giving my PC a static IP and using a UDP tester to send packets,
> however I can only receive packets (on the FPGA side) if I
> broadcast the IP address. When I try to send a specific IP
> address to the FPGA, nothing is transmitted, ethereal doesn't even
> sniff it. So I'm guessing I need to do something on the PC side,
> so it knows that there is a valid IP address associated with the
> FPGA...How would I go about doing this?

Is your FPGA responding to ARP requests? If you're only sniffing UDP
packets, you're not seeing the whole story.

Dave

--
D.a.v.i.d T.i.k.t.i.n
t.i.k.t.i.n [at] a.d.v.a.n.c.e.d.r.e.l.a.y [dot] c.o.m

On Apr 20, 12:51 pm, David Tiktin <dtik...@nospam.totally-bogus.com>
wrote:
> On 20 Apr 2007, meo2...@gmail.com wrote:
>
> > I am setting up a point to point connection between a PC and an
> > Ethernet PHY chip interfaced with a MAC layer on an FPGA. I am
> > giving my PC a static IP and using a UDP tester to send packets,
> > however I can only receive packets (on the FPGA side) if I
> > broadcast the IP address. When I try to send a specific IP
> > address to the FPGA, nothing is transmitted, ethereal doesn't even
> > sniff it. So I'm guessing I need to do something on the PC side,
> > so it knows that there is a valid IP address associated with the
> > FPGA...How would I go about doing this?
>
> Is your FPGA responding to ARP requests? If you're only sniffing UDP
> packets, you're not seeing the whole story.
>
> Dave
>
> --
> D.a.v.i.d T.i.k.t.i.n
> t.i.k.t.i.n [at] a.d.v.a.n.c.e.d.r.e.l.a.y [dot] c.o.m

No I have not implemented ARP in my MAC, I guess that is my next
step. Thanks for your , I'm sure it sounded like a dumb question,
but you'll have to forgive me, I'm new to networking.

meo2662@gmail.com wrote:
> No I have not implemented ARP in my MAC, I guess that is my next
> step. Thanks for your , I'm sure it sounded like a dumb
> question, but you'll have to forgive me, I'm new to networking.

I'm not sure we would say that ARP is part of the MAC. It is part of
the layer2 to layer3 "glue."

If you want to test some more before you impemented ARP in your FPGA,
you could probably set a static ARP entry in your sender's ARP cache,
associating the MAC address of your FPGA solution with the IP address
you wish to use for it.

rick jones
--
denial, anger, bargaining, depression, acceptance, rebirth...
where do you want to be today?
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...