>>> On Wed, Nov 14, 2007 at 4:21 PM, in message <[EMAIL PROTECTED]>, "Spracklen, Ken" <[EMAIL PROTECTED]> wrote: -snip- > Recently we started planning for Linux guests to access data on the z/os > lpars via hipersockets. As part of that process, we defined a new > hipersocket, IUTIQDEF, to the z/VM TCPIP guest profile and added the > IUTIQDEF device to the OSPF config for MPROUTE (same subnet as the > IUTIQDFF interface).
So, since both interfaces are in the same subnet, how is z/OS supposed to know which interface to send packets over, and vice versa? Particuarly before the dynamic routing protocols attempt to figure things out. (And I doubt they'll be very successful.) > We then created a new guest lan (glan01 with type > hipersocket and used nicdef/couple commands for a Linux guest and the > TCPIP guest to use that hipersocket guest lan. What are the IP addresses, subnet masks and default gateways on the z/OS and z/VM side? What are the IP addresses, subnet masks, and default gateways on the guest LAN? As Alan Altmark always says, drawing a picture would be a good idea to illustrate what you're trying to do. > The problem is that I could not ping the ip address of z/VM IUTIQDEF > interface from the zOS systems nor ping the hsi1 ip address on the Linux > guest. That's a really bad sign, since they're only one hop away from each other. > A q lan glan01 det indicated both guests connected but the TX/RX > counts were 0 and the discards were high. I don't know that this is relevant yet, since you say you can't even ping z/VM from z/OS. There wouldn't be any traffic getting to the guest LAN. > In looking at the matter, we came up with several questions that we are > hoping someone can help us with. > > 1) Is the above scenario possible or recommended? We are hoping to use > the guest lan concept to conserve on real hipersocket devices needed for > Linux guests. Does routing work the same way (via the a lookup table) > for a hipersocket guest lan as it does on a real hipersocket network? Yes, since nothing except CP knows that there is any difference between a real HiperSocket and a virtualized one. > 2) Would the above scenario work if the new guest lan was configured as > QDIO? Is there much savings in cp cycles and memory by using a > hipersocket guest lan vice a qdio guest lan? The answer to the first question is "no, it will work (or fail) exactly the same." I would have to let someone who knows something about guest LANS answer the performance question. > 3) In the documentation we have encountered, we have seen examples of a > z/OS hipersocket concentrator and a Linux network concentrator. Does > someone have an example of a z/VM TCPIP/MPROUTE concentrator? Can z/VM > TCPIP/MPROUTE support routing between hipersockets, osa's, and guest lan > (hipersockets and/or qdio)? Which type of concentrator is recommended? I'm 99% sure z/VM can do it. The question I have is why would you want to? Use VSWITCH for the Linux guests for any traffic going through the OSA interfaces, and some sort of HiperSockets concentrator for anything going to z/OS. > 4) In the scenario of the z/os hipersocket concentrator, the z/os is the > router and there are a few Linux guests attached to the hipersockets. I > was wondering if someone could clear up my understanding how that Linux > guests can route data to an ip address out on the network beyond z/os > tcpip. Again, I wouldn't even try to do that. Use the HiperSockets to talk to z/OS and z/OS only. Everything else should go out the VSWITCH. Along with using VSWITCH, I would then start to question the use of any dynamic routing protocols within z/VM or Linux. Let the routers do that, since that's where that work really belongs. VSWITCH was designed with one of the goals being the elimination of dynamic routing "stuff" chewing up valuable mainframe CPU cycles. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
