On 30.05.2002 at 04:00:34, Dave Myers <[EMAIL PROTECTED]> wrote:
> What is best network design
> for a z800 with two OSAx cards.
The one that works ;) Sorry, couldn't help myself...
> Should the two OSAx cards be placed on different network segments for any
> reason?
Yes. Having the OSAs in different subnets will actually reduce some of the
complexity of your routing [1]. If you're looking at using a dynamic routing
configuration ({O}MPROUTE and friends) then this is the way you want to go.
Optionally, you can connect each OSA to a different router to further increase
your RAS.
> I'm confused on the use of hipersockets, guest lans, iucv, the z/VM tcpip
> "hub" etc.
> Are there any good presentations that will help me?????
Don't know of any presentations, sorry... There is a Redbook called "zSeries
Hipersockets" which tells you how to configure Hipersockets, and mentions Guest
LAN briefly. It's probably less than what you'd like, but it's a start. Also,
in the past I have found some interesting material at IBM's Networking site --
go to http://www-1.ibm.com/servers/eserver/zseries/networking/ and look
around.
A couple of hints:
- Hiperspockets support was introduced at z/OS 1.2, so your OS/390 LPAR will not
be able to use it. It will have to use OSA directly, and any communications to
other systems will be either via CTC, via a shared OSA port, or out through your
network.
- If your 30-50 Linux guests do not need to be kept apart from each other, they
can all access the one zLAN[2]. Keeping Rob's observation in mind, defining a
HiperSockets CHPID and dedicating the devices to your Linux guests will save
some overhead in your z/VM system if your guests are not network-intensive.
- If you do need to keep your Linux guests separated for any reason, remember
that you can only have four HiperSockets CHPIDs per CEC. This may force you
into using Guest LAN (or IUCV or vCTC) for some guests.
As we mentioned in the ISP/ASP Redbook, these things can't really be designed in
isolation of your network people. If they don't understand z/VM, HiperSockets,
etc, then that's fine: just draw the diagrams so that they look like a discrete
server implementation, and get their advice. Then draw the box labelled "z/VM"
as appropriate, and change the labels "router", "switch" and "hub" to "z/VM
TCPIP or Linux router" and "zLAN".
> I noticed there's a future redbook that will address this area....but I need
> info now....
A lot of the network design stuff discussed in the ISP/ASP book is still
relevant, only now we have new options in the form of zLANs. If you haven't
already, have a bit of a look there; it might offer more hints.
Cheers,
Vic Cross
[1] Routers tend to be able to resolve multiple routes via different subnets
easier than multiple routes over the same subnets, due to additional
complications that occur in getting to multiple routers over the same 'wire'.
It will work, but things like OSPF Multipath (which you should look at in order
to balance traffic across the OSAs) may not work predictably.
[2] zLAN, for zSeries LAN, is what I call our 'emulated' LAN technologies
(HiperSockets and Guest LAN), since the terms 'virtual LAN' and 'emulated LAN'
both have existing meanings in the network world.
--
Vic Cross MACS mailto:[EMAIL PROTECTED]
Networking, Linux, on zSeries and S/390
