Description

  • 1G SFP interfaces on QFX5120-48YM fail to establish a link when connected to peer devices that enable auto-negotiation.

Symptoms

  • The peer interface shows Link status: Down in the show interfaces output.
  • The local interface shows physical up in the local show interfaces output.

Physical interface: ge-0/0/10, Enabled, Physical link is Up
  Interface index: 668, SNMP ifIndex: 536

 

  • Negotiation shows in the "show interface extensive" output as incomplete

  Autonegotiation information:
    Negotiation status: Incomplete

 

 

Solution
  • Disable auto-negotiation on the peer device.  Set the connection to 1000 Mbps Full-Duplex and ensure that auto-negotiation is turned off.
  • No configuration changes are needed on the QFX5120-48YM.
  • Other devices without auto-negotiation capability may not be affected
  • For a list of compatible transceivers, please refer to our documentation for QFX5120-48YM Transceivers, where a note is added: "Autonegotiation is not supported"


MODEL TYPEMODEL NUMBERPART NUMBERINTRODUCED RELEASENOTE
1 Gigabit EthernetCTP-SFP-1GE-LX740-011614Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetCTP-SFP-1GE-SX740-011613Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetEX-SFP-1GE-LH740-011612Junos OS 23.4R2Autonegotiation is not supported.
1 Gigabit EthernetEX-SFP-1GE-LX740-011614Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetEX-SFP-1GE-LX40K740-017726Junos OS 23.4R2Autonegotiation is not supported.
1 Gigabit EthernetEX-SFP-1GE-SX740-011613Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetEX-SFP-1GE-SX-ET740-011613Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetQFX-SFP-1GE-LX740-011614Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetQFX-SFP-1GE-SX740-011613Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetSFP-1G-LH-C740-011612Junos OS 23.4R2Autonegotiation is not supported.
1 Gigabit EthernetSFP-1G-LX-C740-011614Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetSFP-1G-SX-C740-011613Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetSFP-1GE-LH740-031849Junos OS 23.4R2Autonegotiation is not supported.
1 Gigabit EthernetSRX-SFP-1GE-LH740-011612Junos OS 23.4R2Autonegotiation is not supported.
1 Gigabit EthernetSRX-SFP-1GE-LH-ET740-031468Junos OS 23.4R2Autonegotiation is not supported.
1 Gigabit EthernetSRX-SFP-1GE-LX740-011614Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetSRX-SFP-1GE-LX-ET740-011614Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetSRX-SFP-1GE-SX740-011613Junos OS 22.4R1Autonegotiation is not supported.
1 Gigabit EthernetSRX-SFP-1GE-SX-ET740-011613Junos OS 22.4R1Autonegotiation is not supported.


 
Modification History
2026-01-15 : Article Created