On Thursday, 01/10/2008 at 01:58 EST, "Schuh, Richard" <[EMAIL PROTECTED]> 
wrote:
> We are in the process trying to convert our TPF guests to VSWITCH and 
are 
> getting the messages 
> 
> HCPSWU2833E Error 'E005'X adding IP address nn.nnn.nnn.nnn for VSWITCH 
SYSTEM 
> VMVSW1
> HCPSWU2833E IP address is already in use on the LAN. 
>   
> Everything seems to be working in spite of the messages (which are of 
concern 
> to the operators). I suspect that the messages are the result of the IP 
> addresses being reassigned to different TPF guests after the previous 
users 
> have logged off. Is this plausible? If so, how do I prevent the 
messages? 

OK.  Class is now in session.  :-)

When the guest registers the IP address:
1. If the IP address is already registered on this *virtual NIC*, reject 
the request with "in use on adapter" (E005) error.
2. If the IP address is already registered on the coupled VSWITCH, reject 
the request with "in use on LAN" (E00A).
3. Otherwise, respond "OK" to the guest. 

At this point the guest is a happy camper and can communicate within the 
VSWITCH.  CP will attempt to register the IP address with the OSA. 

4. If the OSA reports a problem registering the IP address, a message is 
issued to the guest's console.  Local communication is unaffected, but the 
guest will not be able to communicate with the outside network.  A QUERY 
NIC DETAILS will tell you if your IP address is local-only or not.

If the OSA gives E005, then another LPAR, a guest, or another VSWITCH 
sharing the port has previously registered the IP.  If OSA gives E00A, 
then the IP address is in use either on another OSA port OR elsewhere in 
your network.

Having to explain that is one of the reasons I tell people that sharing an 
OSA (with anyone) used by a VSWITCH is a Bad Idea as it becomes a left 
hand-right hand problem.  With Link Aggregation, sharing an OSA would be 
deadly, so the z9 has the ability for us to "lock" the adapter, but we 
don't do that with a non-Link Agg. VSWITCH.

> It would appear that a NETSTAT DELARP command prior to reassigning an IP 
address 
> to a TPF guest would do the job, but I would think that the destruction 
of the 
> virtual machine ay logoff would be all that is necessary.

DELARP does not delete IP registrations in the OSA.  It deletes the ARP 
cache in the OSA, where the MAC addresses of other hosts are found.  If 
you need to delete registrations, then you need to use OSA/SF or reset the 
chpid.

> What is the down side, if any, of using DELARP?

It briefly slows down subsequent traffic until the ARP cache has been 
repopulated. In fact, other than activating tracing at the direction of 
the Support Center, you really shouldn't do anything with the controller. 

Alan Altmark
z/VM Development
IBM Endicott

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