Dennis's network people must hang out with mine or read the same doc or something. They too want OSAs on their very own little subnets.
I finally managed to get them to take 1 port off each card on the test box so that I could at least test VSWITCH. Still haven't approached the subject about production. The cool thing about the VM routing thing though is that I can float that guest LAN subnet anywhere I want it to be :) - really good for disaster tests and those who move their datacenters all over the place. Marcy Cortes This message may contain confidential and/or privileged information. If you are not the addressee or authorized to receive this for the addressee, you must not use, copy, disclose, or take any action based on this message or any information herein. If you have received this message in error, please advise the sender immediately by reply e-mail and delete this message. Thank you for your cooperation." -----Original Message----- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Alan Altmark Sent: Wednesday, August 02, 2006 13:46 To: IBMVM@LISTSERV.UARK.EDU Subject: Re: [IBMVM] VM TCP/IP Routing Question On Wednesday, 08/02/2006 at 02:11 EST, Dennis Schaffer <[EMAIL PROTECTED]> wrote: > Please understand that each of my OSA adapters are connected to different > IP subnets (because, my network folks say, that provides optimum > redundancy: completely different network hardware, from the OSA to the > switches/routers, etc., all down the line). IMO that capability is better provided by trunked switches with backup OSAs connected to each switch. All in a single set of subnets that span physical switches. That moves all the routing decisions down into the switch/router where it belongs. > As a result, I'm not sure the physical redundancy automatically supported > by VSWITCH will really work for my installation. The examples I've seen > with automatic VSWITCH failover seem to assume all OSAs are connected to > the same IP subnet. If the OSA is plugged into a trunk port, then it can carry data for multiple subnets. This is what VLANs are all about. The assumption is that all OSA ports associated with a VSWITCH have access to the same subnets/VLANs. > With that in mind, it seems that moving the network connection of multiple > zLinux systems to VSWITCH moves the routing function from a single IP stack > (VM TCPIP) to each of the zLinux instances. Thats the additional > management and automation I referred to in my previous note. Also, I'm not > sure the combined overhead of running OSPF in each zLinux instance won't be > greater than handling all routing from one stack. > > Am I off-base (at least in regards to this question)? IMO, you don't need dynamic routing in the guest - you need a robust switch and VLAN implementation. Alan Altmark z/VM Development IBM Endicott
