[ofw] enable/disable device changes IPoIB physical address??

[Tzachi Dar]

Hi Jeremy, 

I'll try to give you some background about the problem you see, and the
best way that I can see of how to solve it:

The main issue starts from the fact that IPOIB is trying to make windows
believe it is an Ethernet device. One of the differences between the two
systems (Ethernet and IB) is that on Ethernet each port is identified
using a 6 bytes Mac while on IB each port is identified with 16 bytes
GUID.
The WinIB stack supports two ways to solve this problem:
The first is use some counter (starting at 2-0-0-0-0-0-1 and growing)
that is being used to report the address to windows. This is the method
that you are using and it should work although it has some problems.
The preferred way is to create a one to one mapping between the 16 bytes
of the guids and the 6 bytes of the MAC. Although this seems impossible,
it is possible since the 16 bytes numbers come in  different series,
which means that there is only a limited number of Guids that can be
seen.
So, if the code in WinIB will recognize the cards that you have as cards
that belong to some predefined series your problem will be over.
Mellanox, Voltaire and Silver-Storm have tried to make sure that their
cards will have a one to one mapping. And I  suggest that you will do
the same.

So, there are two questions that I would need to know in order to help
more:
1) who is the manufacture of your cards?
2) what are the guids that you are using? (you can use vstat to get the
physical guids).

Thanks
Tzachi

> -----Original Message-----
> From: ofw-bounces at lists.openfabrics.org 
> [mailto:ofw-bounces at lists.openfabrics.org] On Behalf Of Jeremy Enos
> Sent: Wednesday, August 01, 2007 11:16 PM
> To: ofw at lists.openfabrics.org; David A. Norris
> Subject: [ofw] enable/disable device changes IPoIB physical address??
> 
> Hi-
> We're attempting to create some automated scripts to change 
> IP settings w/ IPoIB adapters, and running into some strange 
> issues.  Thus far, we've been trying to identify the correct 
> NIC/port by the physical address, which seems to be the same 
> on all hosts.  This is fine, as we were looking for a 
> reliable way to identify the port each time.  
> However, it's *not* reliable.  For some reason, disabling and 
> re-enabling the device actually changes the physical address 
> that ipconfig reports each time.  Only a reboot of the host 
> resets it to the initial address (02-00-00-00-00-01).  We're 
> also guessing that the phys addy that gets assigned on each 
> re-enabling of the device is based on some timestamp, as the 
> disparity between them increases when there is more time 
> between the re-enabling.  Why is this address ever changing 
> in the first place?
> 
> Environment:
> OS: Win2003 x64
> HCA:  MT25208
> 
> Another explanation I'm seeking is why setting static IP info 
> via the GUI doesn't seem to take.  No errors when I hit "Ok", 
> but when I go back to the tcp/ip settings again, it's all 
> reset to dhcp.  Even when command line utilities like netsh 
> are used to change the IP from the cmd line, the GUI does not 
> reflect it.  Anyone else see this?
> 
> thx-
> 
>     Jeremy Enos
>     NCSA
> 
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