У меня отрабатывает loopback:
Physical interface: xe-2/0/0, Enabled, Physical link is Up
Interface index: 187, SNMP ifIndex: 591, Generation: 190
Link-level type: Ethernet, MTU: 1514, MRU: 1522, LAN-PHY mode, Speed: 10Gbps, BPDU Error: None, Loop Detect PDU Error: None,
MAC-REWRITE Error: None, Loopback: Local, Source filtering: Disabled, Flow control: Enabled, Speed Configuration: Auto
Pad to minimum frame size: Disabled
Device flags : Present Running Loop-Detected
Трансивер какой у тебя в этом порту?