[ixp1200] Connectivity questions

[Yitzchak M. Gottlieb]

On Tue, 1 Oct 2002, Magesh Kannan wrote:

> Hi,
> 
> This is a question for the guys at Princeton. Can you please briefly
> describe your hardware setup? I mean 
> 
> 1. what cable (cross-over/straight-thru) you use to connect the ethernet
> ports on the IXP1200 to the outside world.
>

It depends.  If we are connecting to a PC with an ethernet card, we use a
standard cable.  If we are connecting it to another IXP, we use a cross-over
cable. 

> 2. if you always use a switch/hub between a host and the ixp1200 ethernet
> ports.
>

We haven't used a switch or a hub.

>
> 3. what ethernet card and driver do you use on the machines that you
> connect to the IXP1200 for the IPmm experiment.
>

Our cards are Kingston cards (DEC Tulip based).  We use the standard Linux
driver (included in the Red Hat distribution).

> 4. if you force the speed on any of these ports to 10 Mbps etc.
> 

We don't force the speed on the ports.

> 
> If I force the speed on the linux PC's interface to 10 Mbps (using
> mii-diag), the link LED (in the LED bank) comes on, but when I try to send
> traffic, there is some debug output on the IXP1200's serial port
> (indicating packet reception) initially. After some time, there is no
> further output and I get carrier errors on the PC (found from ifconfig).
> 

I don't think I've seen this before.

> The only configuration in which I have been able to make the IXP1200 ports
> receive packets is this
> 
>  Linux PC's eth1 <--- STRAIGHT-THRU ----> 10 Mbps ONLY HUB 
> 	<----- CROSS-OVER ----> 1XP1200 ETH port
> 

This makes sense: the IXP port and the hub's ports are both crossover ports
(meaning they expect to connect to a PC with a straight-through cable).  Since
they are of the same type, they need a cross-over cable to connect them.

Zuki

-- 
Yitzchak Gottlieb
zuki at CS.Princeton.EDU