Dan Smith wrote: > BH> Can I ask what the addresses were? > > I'm not sure what you mean. You want to know what the duplicated > address was? My flawed byteorder adjustment caused me to have two > fe80::X addresses on the restored interface. Ok, I was wondering if you had two link-locals because when you moved from machine to machine the MAC changed. > I've since added a check to ignore non-global scope addresses, which > works nicely. Well, in most cases you could ignore the global addresses as well, since if they were auto-configured they'll be generated again on the next Router Advertisement. That's why they're removed on an ifdown, but the permanent ones aren't (any more). > BH> Did you move from VM to VM so the underlying NIC MAC address > BH> changed? > > No, the MAC doesn't change because I reconstruct the interface on the > other side with the original MAC address. The netns and netdev code > assume that you're migrating your entire network namespace, which > includes all the devices within. Ok, I forgot about the underlying device being moved as well, that makes sense. > BH> Again, I don't know your typical user for C/R. For example, with > BH> IPv4 you save all the addresses, but if one of them was configured > BH> via DHCP, you could have an address conflict when you restore it, > BH> since there's no way to know if it's been handed-out to another > BH> system in the meantime. Or does a typical C/R user only have > BH> static addresses? > > I think that the expectation is that if you're migrating network > connections, you are going to have to be in your own netns and have > your own interface. If DHCP is in play, then you're going to be > migrating dhclient along with your app anyway. Ok, so dhclient6 too :) > BH> With IPv6 it gets worse because the link-local will get created > BH> automatically, and if you're in a VM it will probably be somewhat > BH> random. Then when you move to another VM you'll get another > BH> virtual NIC with a different MAC address. Since the global > BH> address is going to be based off the same lower 64-bits, you'll > BH> wind-up with a second global in most situations (since you're > BH> restoring the original address). > > Well, I'm not sure of your use of "VM" in this case. I think the > typical usage here will be a container that behaves like a VM. As I > said above, you'll have your own virtual interface and your MAC > address will go with you. Yeah, I'm just using the wrong terminology sometimes, like you said, it's a container behaving like a VM. -Brian _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
