My site is also planning to use a VLAN aware VSWITCH.

Presently I have all TCPIP communications uses the VSWITCH, except for a
TCPIP stack that connects directly to the OSA which is used for systems
programming functions.

What would be required for the systems programmer's TCPIP stack to have
recognize the VLAN?  I have scanned the TCPIP configuration options and I am
not able to determine what parameters would handle this.  Would it be
necessary to place it on the VSWITCH?

Thanks.

Cecelia Dusha

-----Original Message-----
From: Alan Altmark [mailto:[EMAIL PROTECTED] 
Sent: Friday, March 23, 2007 9:56 AM
To: [email protected]
Subject: Re: Setting up VLAN Aware VSWITCH

On Friday, 03/23/2007 at 09:08 AST, Mark D Vandale <[EMAIL PROTECTED]>
wrote:
> We were considering setting up a VLAN aware VSWITCH on zVM 5.2.  The 
> LAN Administrator is concerned with the possibility of looping 
> scenarios due
to
> parameters I am not familiar with.  For example he is asking about 
> what "scanning tree parameters"

Make that "spanning tree".  :-)

> are being set, encapsulation protocol, dot.q, neg/nonneg and VTP ?  It 
> doesn't look like I can set any of these parameters on zVM.  So how 
> does this working when using a TRUNK method
and
> is this discussed in any manual that I can share with the 
> administrator
?

The VSWITCH is IEEE 802.1q ("dot1.q") conformant.  It does not support VTP,
though we do use GVRP (a VLAN registration protocol) to tell the switch what
VLANs are in use.

> Also, I don't know if this makes any difference, the current plan is 
> to
use
> 2 osa's, vlan aware, and having 2 vswitches.

Why two VSWITCHes? Remember that each VSWITCH will want two OSAs: one
primary and one backup.  If you are carrying different VLAN sets on each
VSWITCH, each can use the other's OSA as backup.  It is also my
recommendation that you do not share an OSA in use by a VSWITCH,
*especially* if it is VLAN-aware.  The last thing you want is a fight
between two VSWITCHes about whether a VLAN is in use.  Yes it is, no it
isn't, yes it is, no it isn't....  If you choose to go down this path,
define the VSWITCH with NOGVRP.

As long as you don't connect a routing guest to two VSWITCHes at the same
time, you shouldn't have any spanning tree problems.

Alan Altmark
z/VM Development
IBM Endicott

Reply via email to