Hi John, thanks for volunteering! I have dug into the magma issue a bit more. it is difficult to say. i can describe my test case, and YMMV. (if you need more detail just ping me off list, i suspect your own investigation path would bear interesting fruit) -take latest rc 2 Pharo image -force use new network class var -force default on initialization to use new network -install OSProcess -install Magma -fix os process launching issue in magma code -stop magma changing OS x display resolution (annoying) -run magma test suite -<launches 4 images> so the first thing to check is that the os process launch does not have the side-effect of killing the network. i suspect not, there are so many hooks to reinit. i tried to force server creation to the local host address, if so the test failure reduces to this: | if socket | if := NetNameResolver localHostAddress. socket := Socket newTCP. socket listenOn: xxxxx backlogSize: 50 interface: if. socket isValid where if is an ipv6 structure. socket isValid returns false, so it is dead. However, if I look on the shell mike-mac:~ mike$ lsof -i4 | grep Squeak Squeak 9944 mike 9u IPv4 0x6a9f66c 0t0 TCP *:* (CLOSED) Squeak 9944 mike 10u IPv4 0x6ab0a68 0t0 TCP *:* (CLOSED) Squeak 9944 mike 11u IPv4 0x6a75a68 0t0 TCP *:* (CLOSED) Squeak 9944 mike 12u IPv4 0x8e8a270 0t0 TCP *:* (CLOSED) Squeak 9944 mike 13u IPv4 0x6a9ee64 0t0 TCP *:* (CLOSED) Squeak 9944 mike 14u IPv4 0x6aa4a68 0t0 TCP *:* (CLOSED) Squeak 9944 mike 15u IPv4 0x6a94a68 0t0 TCP *:* (CLOSED) Squeak 9944 mike 16u IPv4 0x8e86e64 0t0 TCP *:* (CLOSED) Squeak 9944 mike 17u IPv4 0x6a7966c 0t0 TCP *:* (CLOSED) Squeak 9944 mike 18u IPv4 0x6539e64 0t0 TCP *:* (CLOSED) Squeak 9944 mike 19u IPv4 0x919066c 0t0 TCP *:* (CLOSED) Squeak 9944 mike 21u IPv4 0x9192a68 0t0 TCP *:* (CLOSED) Squeak 9944 mike 22u IPv4 0x918866c 0t0 TCP *:* (CLOSED) mike-mac:~ mike$ lsof -i6 | grep Squeak mike-mac:~ mike$ so i have lots of dead ipv4 sockets, and no ipv6 ones... even though netname resolver returned an ip6 structure. i guess i don't know really how i expect it to work. maybe just using the wrong api... I also tried clamping the interface to a known ip address on my machine i.e if := NetNameResolver addressForName: '192.168.1.15'. but it does not work either. hope that debugging helps in any way. cheers, Mike