This article provides the steps to enable MAC bypass on EX devices to authenticate dot1x, multiple supplicants at the switch level instead of using interfaces.

set protocols dot1x authenticator interface ge-0/0/30.0 supplicant multiple

set protocols dot1x authenticator interface ge-0/0/31.0 supplicant multiple

Supplicant multiple on ge-0/0/30.0 and ge-0/0/31.0 allows multiple client devices on each port to be handled and authenticated individually, rather than limiting the port to a single supplicant. 

The two static MAC entries add aa:bb:cc:dd:ee:01 and aa:bb:cc:dd:ee:02 to the 802.1X static MAC bypass list. A matching device can bypass 802.1X authentication and be permitted onto the network.

set protocols dot1x authenticator static aa:bb:cc:dd:ee:01

set protocols dot1x authenticator static aa:bb:cc:dd:ee:02

Important scope detail: as written, the static entries are not tied to either interface. Juniper documents an optional interface qualifier for restricting a static MAC bypass entry to specified ports. Without that qualifier, do not assume these MAC addresses are limited to ge-0/0/30.0 and ge-0/0/31.0.

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/statement/interface-802-1x.html?doc-askai-citation

In effect, the two ports support multiple clients, while the listed MAC addresses are configured for authentication bypass. These commands alone do not specify VLAN assignment, RADIUS policy, or other access restrictions; check the rest of the 802.1X and switching configuration to determine the resulting network access. Juniper’s static-MAC documentation also supports VLAN assignment as an optional setting.