Description

On EX4400-VC setup, the interface on the back up chassis remains down after a reboot.

Symptoms

In a EX4400-VC setup, if the VC is rebooted, the interfaces on the backup chassis does not come up. 

The issue might not be seen on every reboot. But should be recreated after on an average 2-3 reboots.

The issue that interfaces on the Junos are seen as up/down. However in the BCM, it appears as UP. This is because there is  auto-negotiation mismatch between BCM and Junos. On Junos is detects as incomplete.

 
 
user@lab> show interfaces terse ge-1/0/0    
Interface               Admin Link Proto    Local                 Remote
ge-1/0/0                up    down
ge-1/0/0.0              up    down eth-switch
 
 
 
user@lab> show interfaces ge-1/0/0 extensive | match neg 
  MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled, Flow control: Enabled, Auto-negotiation: Enabled, Remote fault: Online, Media type: Copper,
  Autonegotiation information:    
    Negotiation status: Incomplete
 
 
user@lab> show interfaces ge-1/0/0 extensive | match duplex 
  Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Link-mode: Half-duplex, Speed: 1000mbps, BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None,
 
 
TFXPC1(lab vty)# set dcbcm bcmshell "ps ge0"            
HW (unit 0)
                 ena/        speed/ link auto    STP                  lrn  inter   max   cut   loop
           port  link  Lns   duplex scan neg?   state   pause  discrd ops   face frame  thru?  back   encap
       ge0(  2)  !ena   1    1G  FD   SW  Yes    Block          None   FA  SGMII  1518                IEEE

 

Solution

This issue can be recovered by simply bouncing the port.

Modification History

2025-09-18 : Article Created