I have question about LAG and fail-over scheme. In example i would like to configure the interface of ge-0/0/0 and ge-0/0/1 into LAG. Then I will configure into ae0. Since the ae0 will provide maximum speed of 2 x 1G, my question is, if the link at ge-0/0/0 is down (or the cable is cut), does ae0 still up?
You need to set minimum-link value to the interface ae0. let's say you set it as 1.
set interfaces ae0 aggregated-ether-options minimum-links 1
so when interface ge-0/0/0 down, because you set the minimum link to the ae0 is 1 link, the ae0 will stay up. Unless the both link down.
Minimum-link value is also not needed, if one of the links in the aggregate-ethernet bundle is up then ae interface will remain up.