Error Device ae1 Not Found

I recently ran into a problem on an EX series switch – after already setting interfaces ae0 ae1 and ae2 up.

Here was my configuration:

root@lab-ex-1# show interfaces ae1
aggregated-ether-options {
    minimum-links 1;
    link-speed 10g;
    lacp {
        passive;
        periodic fast;
    }
}
unit 0 {
    description lab-mx1-ae1;
    family ethernet-switching {
        port-mode trunk;
        vlan {
            members 800;
        }
    }
}

The problem was that after I had set these interfaces up I was getting this error on ae0, ae1 and ae2

root@lab-ex-1# run show interfaces ae0 statistics
error: device ae0 not found

root@lab-ex-1# run show interfaces ae1 statistics
error: device ae1 not found

root@lab-ex-1# run show interfaces ae2 statistics
error: device ae2 not found

This is really easy to overlook but I had missed an important step. I needed to allow a certain amount of aggregate devices.

set chassis aggregated-devices ethernet device-count 100

I set this to 100 because I did not see any use in having to add more interfaces to this later on.