Re: 回复： Does OSA Express2 Ethernet su pport zVM layer2

[russell . gendreau]

Greetings,

 

 

I saw this post and would like to get some verification on running both layer 2 
and layer 3 on the same OSA.

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? 

Would we be able to also have other LPARS either z/VM or z/OS share this same 
OSA with layer 3 as well ?

From my understanding you had to have OSPF to share the OSA’s with other LPARS 
( mainly with the z/OS )

 We currently have the new Z10 box

 

Thanks

 

 Russell Gendreau

Time Customer Service, Inc.

813-554-2064

 



From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On Behalf 
Of Anson
Sent: Monday, September 21, 2009 8:28 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: 回复： Does OSA Express2 Ethernet support zVM layer2

 

Ronald,

 

Thanks for your information! I checked our z900's configuration. It should be 
OSA Express in stead of Express2.  

 

There is one thing I couldn't understand. The z/OS on another LPAR can work 
well on ipv6. They used the same OSA adapter. 

Anson Y.



发件人： Ronald van der Laan nl50...@gmail.com
收件人： IBMVM@LISTSERV.UARK.EDU
已发送： 2009/9/18(周五), 下午7:24:14
主 题： Re: Does OSA Express2 Ethernet support zVM layer2

Anson,

From the top of my head (I can't verify anymore, no access to z900 lpars 
left), both layer 2 and layer modi should be supported (if you are current 
enough on your OSA microcode level).
But what won't work on a z900, is sharing the osa with layer 2 and layer 3 
traffic.  As I recall, the first to connect to the OSA could set the mode (2 or 
3) and all other shared connections have to use the same mode (just like the 
portname).
The restriction got lifted with z990, there you can use the same shared OSA, 
mixing layer 2 and layer 3 connections.

Ronald van der Laan

 



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Re: 回复： Does OSA Express2 Ethernet su pport zVM layer2

[Alan Altmark]

On Tuesday, 09/22/2009 at 08:10 EDT, russell.gendr...@custserv.com 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