On Jan 17, 2007, at 2:58 PM, Tom Duerbusch wrote:
So, in the latest post towards Miguel:
1. I do need a HOME statement for each interface, 30 some odd HOME
statements....right?
If you have VCTCs hanging off each of them, yes.
2. The IP statement on the HOME statement:
a. Cannot duplicate any other IP address in the network
True.
b. Must be in the same subnet as the IP address for the host
(Linux27)
Well, presuming that Linux27 is only *one* of those links. And using
"host" here is confusing. Anything with an IP stack is a "host."
The IP address of the VM side of the point-to-point link is in the
same /30 subnet as the other side of the point-to-point link.
c. Each link, will have its own subnet which contains the IP
address of the link and the IP address of the host.
Yes. Each netmask will be 255.255.255.252. In a /30 network (i.e.,
that netmask) there are four addresses. The bottom one is the
network address. The top one is the broadcast address. That leaves
two real addresses, one for each end of the link.
d. I can't have sequential IP addresses (incremented by 1)
for my
Linux hosts.
Not if they're on different CTCs, because that will violate subnetting.
But if you have Linux hosts then why are you screwing around with
VCTC at all? Just put them on a VSWITCH or Guest LAN segment and let
them use (virtual) Ethernet adapters as God intended, and then you
can have a nice roomy /24 (or whatever) subnet and not have to worry
about it. Put them up against each other if you like.
e. The subnet address associates the IP address on the link with
the IP address for the guest.
....sort of. The VM and Other sides of the link have to be in the
same /30 subnet.
3. My GATEWAY statement seems to be correct
I didn't see anything wrong here.
On a tangent, vswitch.
I am using sequential IP addresses for my Linux machines on the
vswitch. And they are working, even under z/VM 5.2. Am I going to be
facing future problems here. Would it be advisable to start using
addresses on different .252 subnets? I do believe that vswitch is a
switch and the VM stack was a router and they may be more dis-similar
than similar. But in the areas where they are similar....
No. Your Linux guests on a virtual LAN segment can have adjacent
addresses and behave just like Linux machines on any other network
anywhere in the real world. You want to get away from crazy
subnetting by doing away with VCTC and IUCV connections in so far as
possible.
Adam
