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
