Re: testing cabling and NIC hardware with one machine

[Christopher Paul]

On 10/25/17 10:20 PM, Tony Sarendal wrote:

Configure the interfaces into separate rdomains.

/T
Yup that works. For sure I know the packets are traveling along the wire 
using rdomains now. But I wonder how much of the RTT on each packet is 
due to the kernel/driver/rdomain code now. And also due to this test 
platform being a virtual machine in Linux/XEN environment.


The ping response I get is, across the wire, more than what I got 
without the rdomains: round-trip min/avg/max/std-dev = 
0.415/0.530/0.890/0.165 ms, not bad but not what I'd like to see from 
10GbE. A large std-dev, relatively, and not quite as low as I'd expect 
for 10GbE. As this test instance currently is a Xen guest, the interface 
is an xnf driver; the 10GbE is bridged on a Linux Xen server's device. 
But based on this working, I may be able to justify some hardware 
allocations happening so I can build a platform natively OpenBSD.


Thanks, Tony, for the good tip.

CP

testing cabling and NIC hardware with one machine

[Christopher Paul]

Hi Misc,

I have been tasked with setting up a benchmark platform to test NICs and 
network cables. I'd like to do this on one PC. So I want to send packets 
of different protocols out of one interface and into the other, 
across/thru the NICs and whatever type/lengths of cabling I am using. 
The problem I am having is that if I configure two interfaces on the 
same server, either on the same network or not, the kernel is smart 
enough to know to not need to use the actual wire (ethernet cable) in 
order to transmit the packet from one interface to the other. Which I 
guess I was aware of, and of course it makes a lot of good sense for a 
normal situation, but in this case, is a block on my project.


So I'm wondering is this sort of kernel-fooling I want to do possible 
with OpenBSD? Or for that matter, any OS?


May be I need to set them up as a bridge? If I did that I could set it 
up with forwarding, yeah? Something like that I guess I will try next.


Many thanks for those of you who read this and offer any ideas && Long 
Live OpenBSD,


CP