LAGG with No Switch - Straight to Hosts

Hi Folks! I’m using the latest stable SCALE version and am trying to setup a LAGG running on 2 NICs that wire straight to two separate VM hosts. The LAGG would use one IP and be accessible by both hosts simultaneously. Essentially I’m trying to setup a LAGG without the switch.

So NIC1 would go to HOST1. NIC2 would go to HOST2. Both hosts would access the TrueNAS server using the same IP.

So - the problem comes in with the Link Aggregation. I can, depending on how it’s configured, get one host to ping/communicate with the TrueNAS server, but not both at the same time.

I can configure two NICs independently with separate IPs and get them to talk to the hosts, but I’d like to use the same IP to talk to the TrueNAS on both hosts.

Do you know if this is a supported configuration or should I just use a switch?

I hope this is clear enough to figure out what I’m trying to do…


EDIT: To clarify - the hosts would have separate IPs, but the TrueNAS would only have one IP.

None of that is going to work.
The NAS cannot have two NICs on the same subnet, much less with the same address.
And link aggregation cannot work without a switch: It distributes multiple connections over multiple wires, but any single link between the server and one client will go through a single wire.


I got that, but I was hoping the TrueNAS would send the return traffic out the same interface it was received on. I guess it probably doesn’t keep a MAC table like a switch does and will just send out whatever interface it thinks is best, regardless of the transmit hash policy (which probably doesn’t do what I think it does).


No, that isn’t the way things work. See:


You want a bridge, not a lagg.

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