We're starting to test hipersockets between Linux guests on z/VM and z/OS systems in separate LPAR's. z/OS is having intermittent trouble pinging one of the four Linux guests, but is fine with the other three. All four Linux guests have no trouble pinging z/OS. Someone suggested that the device addresses used have to be unique among all the LPAR's. E.g. if z/OS in LPAR 1 allocates FC00-FC02, then I shouldn't allocate real FC00-FC02 on z/VM in LPAR 2 to a Linux guest, but should start with FC03 or FC04. I've never heard of such a restriction, and the source of the advice is suspect. Is there such a restriction? I found a Redbook, "e-Business Intelligence: Data Mart Solutions with DB2 for Linux on zSeries", SG24-6294-00, that used the same addresses on z/OS in one LPAR and a Linux guest in another LPAR. Note that the z/OS TCP/IP configuration doesn't specify UCB's, just CHPID numbers, but z/OS allocates the lowest three UCB's on the CHPID.
If the device addresses aren't the problem, what else should I look at? The TCP/IP configurations on the Linux guests are identical, except of course for the IP address. The intermittently-working guest has an IP address that ends in ".1". I know that ".1" addresses are customarily used for routers, but there are no routers in this configuration. Dennis O'Brien My computer beat me at chess, but it was no match for me in kickboxing.
