When using 1 Gigabit SFP optics on the uplink module in EX4300 devices, the uplink interface may not come up and manual intervention may be required to bring up the interface.
This article gives the cause for the interface to not come up and the steps to resolve the problem.
On the uplink modules in an EX4300 switching device, when using 1 Gigabit optics (SFP-T), the interface may not come up.
{master:0} root@EX4300-1> show configuration interfaces ge-0/2/0 description "to EX4300-2"; unit 0 { family inet { address 10.10.10.1/32; } } {master:0} root@EX4300-2> show configuration interfaces ge-0/2/0 description "to EX4300-1"; unit 0 { family inet { address 10.10.10.2/32; } } {master:0} root@EX4300-1> show interfaces ge-0/2/0 terse Interface Admin Link Proto Local Remote ge-0/2/0 up down ge-0/2/0.0 up down inet 10.10.10.1 --> 0/0 {master:0} root@EX4300-2> show interfaces ge-0/2/0 terse Interface Admin Link Proto Local Remote ge-0/2/0 up down ge-0/2/0.0 up down inet 10.10.10.2 --> 0/0
By default, the 1 Gig optics have auto-negotiation enabled and this might cause the Packet Forwarding Engine (PFE) to drop the connection between the two links because the other side connected to the uplink interface is not set to auto-negotiate. This problem is seen on the SFP-T optics:
{master:0} root@EX4300-1> show chassis pic fpc-slot 0 pic-slot 2 FPC slot 0, PIC slot 2 information: Type 4x 1G/10G SFP/SFP+ State Online PIC version 3.2 Uptime 3 days, 15 hours, 23 minutes, 27 seconds PIC port information: Fiber Xcvr vendor Wave- Xcvr Port Cable type type Xcvr vendor part number length Firmware 0 GIGE 1000T n/a Methode Elec. SP7041-M1-JN n/a 0.0 2 GIGE 1000T n/a FINISAR CORP. FCLF8521P2BTL-J3 n/a 0.0 {master:0} root@EX4300-1> show interfaces ge-0/2/0 Physical interface: ge-0/2/0, Enabled, Physical link is Down Interface index: 744, SNMP ifIndex: 619
Disable auto-negotiation and hard code the link speed to 1 Gigabit as shown below:
set interfaces ge-x/y/z speed 1g set interfaces ge-x/y/z ether-options no-auto-negotiation {master:0}[edit] root@EX4300-1# set interfaces ge-0/2/0 speed 1g {master:0}[edit] root@EX4300-1# set interfaces ge-0/2/0 ether-options no-auto-negotiation {master:0}[edit] root@EX4300-1# show | compare [edit interfaces ge-0/2/0] + speed 1g; + ether-options { + no-auto-negotiation; + } {master:0}[edit] root@EX4300-1# commit configuration check succeeds root@EX4300-1# run show interfaces terse ge-0/2/0 Interface Admin Link Proto Local Remote ge-0/2/0 up up ge-0/2/0.0 up up inet 10.10.10.1 --> 0/0