On Tuesday, 09/22/2009 at 08:10 EDT, [email protected] wrote: > I saw this post and would like to get some verification on running both layer 2 > and layer 3 on the same OSA.
Yes, you can run both and they can even talk to each other. In the distant past, layer 2 and layer 3 could co-exist, but they couldn't talk to each other, creating a problem if they were in the same subnet. That was fixed a long time ago (z990?). > So we can now have say a z/VM running Linux guest on a layer 2 to an OSA along > with a layer 3 TCP stack on the same z/VM using the same OSA? Yes. Note that z/VM 5.4 TCP/IP now supports layer 2. > Would we be able to also have other LPARS either z/VM or z/OS share this same > OSA with layer 3 as well ? Yes. > From my understanding you had to have OSPF to share the OSA?s with other LPARS > ( mainly with the z/OS ) Not true. If you are sharing and the OSA is plugged into an access (as opposed to trunk) port on the switch, then everyone is in the same LAN segment and therefore the same subnet. z/VM has the VSWITCH to supply the needed OSA redundancy. z/OS has OSA failover (takeover), but no one seems to use it, depending on OSPF instead to handle the outage. Alan Altmark z/VM Development IBM Endicott
