I finally managed to set up tests simulating migration where the source and target host are different machines which may have different IPs. I'm getting some weird failures, but first the setup itself, since it might be useful. I'm attaching nsqemu.sh, which is based on my earlier qemu.sh. # Steps to run 1. In terminal 1, run $ nsqemu.sh box 2. In terminal 2, run $ nsqemu.sh source 3. In terminal 3, run $ nsqemu.sh target 4. In terminal 2 set up guest network # ip link set eth0 up # dhclient eth0 5. In terminal 2 (source) connect to the server running terminal 1 # socat STDIO TCP4:172.16.1.1:5555 6. Send some data back and forth between terminal 2 (source guest) and terminal 1 (external peer) 7. Initiate the migration in terminal 2 C-a c (qemu) migrate tcp:172.16.55.22:4444 8. Wait for migration to complete, watching terminal 3 (target guest) 9. Attempt to send data back and forth between terminal 3 (target guest) and terminal 1 (external peer) This isn't quite working for me, for reasons I haven't figured out yet # Testing with different source and target host IPs To test this change the IP= lines in the source and target sections so that they're different. This test is mostly working for me; the target drops the connection without breaking continuing connectivity on the target. # Network model The "box" creates an L1 namespace to host everything. It contains a bridge device "br0" with address 172.16.1.1. It's not connected to the outside internet. The peer server runs here. The source and target "hosts" are L2 namespaces, each with a veth attached to br0, and *both* with address 172.16.1.111, default route via 172.16.1.1 Additionally there's a veth directly between the two L2 spaces, used for the actual migration stream. It has addresses 172.16.55.11 and 172.16.55.22. # Weird failure For some reason, after the migration with this setup the target guest receives further incoming data from the peer server, but further outbound data seems to reach the bridge.. but not the server process. br.pcap attached. -- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson