On Wednesday, 02/17/2010 at 05:19 EST, mike.wawio...@barclays.com wrote: > Alan, > > I wonder why you make your final point below. > > 4. Reduces the temptation to share OSA ports (VSWITCH + TCPIP) > > What's the downside of sharing an OSA between the z/VM IP stack and the > VSWITCH?
Sharing means (a) You have to remember it. If the port is changed to a different VLAN, for example, then all users of the port must change. Or placed on a trunk port. (b) You have to explain it and demonstrate to Network Security People how your change management processes ensure that you don't forget and that you don't inadvertantly put the wrong host on the wrong LAN. <shudder> (c) You cannot change the VSWITCH to use things like link aggregation or whatever else may come along. These things always require a single "owner" of the port. Alan Altmark z/VM Development IBM Endicott
