Tom, the 192.168.192.x address is per default a class c address and you use it as a subnetted class b address. I had such a situation at a customer site several years ago. OS390 2.9 did not accept this address and subnet mask, because of violating standards. I have never tried, if z/OS is more "tolerant" to the standard. You might get in trouble with more restrictive ip stacks. Of course, windows ip stack is not a problem, because complying to standards is not a primary domain of windows. ;-)
Franz Josef Pohlen ----- Original Message ----- From: "Tom Duerbusch" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, October 13, 2005 9:34 PM Subject: Subnet mask problem > Well, my requests to the networking group for some networking changes, > ended up being sent to a "level 3 guru". At least I could find some > common terms with networking, but this guy is speaking gibberish<G>. > > > I wasn't paying attention to the IP addresses I've now been assigned, so > I let this one slip thru. They gave me 192.168.192/22. Huh? > > I get the impression that the mainframe now own: > > 192.168.192.x > 192.168.193.x > 192.168.194.x > 192.168.195.x > > So, a thousand addresses should be sufficient<G>. Actually, I made so > many requests that they may be confused. So I'm accepting them and > trying to do things in a piece meal fashion. > > Anyway, in z/VM 5.1, I need a subnet mask and subnet value for this. It > doesn't seem simple. This VM image will have 192.168.193.3. My initial > guess is a subnet mask of 0.0.255.0 and a subnet value of 0.0.3.0 but > that didn't work in my first test. (At this point I don't know if the > "level 3 guy" made the changes correctly or if I didn't make the changes > right. (Right now, this is on the unused IFL side, so I have time for > testing.) Eventually, I'll put in VM's vswitch for support of the Linux > images. > > Background: > > They are not going to be routed. > They are part of a virtual lan assigned to the mainframe. > They are "seg 3". I don't know if that is a term, or a label, like > "third segment" or what. > > What I wanted: > > We have 2 OSA card, each with 2 GBE ports. > We have a 390 engine and an IFL. > I see a 390 lpar plus multiple IFL lpars (all running under z/VM images). > A linux image may be IPL'ed in any of the lpars (so a LPAR can be taken > down for maintenance). > I wanted all IP addresses to be available on any of the 4 GBE fibers. > > So I think that is the virtual LAN that networking setup. Hence they > don't need to do routing. I think that is good. > > Eventually, we will be plugging in the 3 100mb ethernet connections from > the IBM DS6800 dasd subsystem as the DS6800 calls home over the > Internet. Perhaps even the 3 100 mb ethernet connections from the z/890 > (perhaps not on this one as the call home function is still over dial up > phone). > > Also I have two OSA-ICC cards. Each card has two ports of 1000 Base-T > copper connections. One port on each card is configured as ICC. The > other port on each card is another OSA port, not used at this point. > > Boy, a single LPAR with a single IBM 3172 ethernet connection, was much > simpler<G>. But there are many reasons for going to the more > complicated setup. > > Thanks > > Tom Duerbusch > THD Consulting > >
