On Friday, 01/13/2006 at 01:44 CST, Bob Robinson <[EMAIL PROTECTED]> wrote:
> 2 CEC?s each with one z/VM 5.1 LPAR. Each z/VM LPAR has one TCPIP stack, > MPROUTE, two OSA Express?s and one QDIO guest LAN. The Guest LAN?s are > defined with the same subnet, let?s say 10.10.10. CEC 1?s Guest LAN > gateway address is .1 (dot one) and CEC 2?s is .2 (dot two) When TCPIP on > CEC 1 is activated connectivity to the Guest LAN works fine. When TCPIP on > CEC 2 is activated, I can connect to the stack, but not to the Guest LAN > and connectivity to the Guest LAN on CEC 1 is gone. When I shut down CEC > 2?s TCPIP, connectivity returns to CEC 1?s Guest LAN. > > Can someone explain why this does not work and which protocol or law I?m > violating here? Hmmmm.... Violation #1: you took a single subnet (broadcast domain) and broke it in half without putting a transparent bridge between them. Violation #2: you're running MPROUTE after having been issued a summons by the Network Police for Violation #1. Violation #3: Two MPROUTEs, not connected by a transparent bridge (see #1), believe each one owns the 10.10.10 subnet. You are giving your external router migraines. Violation #4: You haven't gone to the zSeries Tech Conference, SHARE, WAVV, or a local z/VM user group where I've taught this subject in detail. Sentence has already been carried out: You are placed into network hell and there you shall reside until you repent. ;-) As you noted, the VSWITCH will solve this problem. A single OSA can be shared by the VSWITCH in each LPAR, creating the necessary transparent bridge. The functions of MPROUTE will be offloaded back into the switch/router where they belong. Alan Altmark z/VM Development IBM Endicott
