Description

When connecting SRX and QFX5110 with 1G link using fiber SFP, the physical interface is down on SRX. However, the interface is up QFX5110.

Symptoms

Topology Example

  SRX345(ge-0/0/9)------------(ge-0/0/10)QFX5110
 

On SRX345

 [edit]
root@SRX345-2# run show interfaces terse   
Interface               Admin Link Proto    Local      Remote
ge-0/0/0                up    down
……
ge-0/0/9                up    down
……
vtep                    up    up
 
[edit]
root@SRX345-2# run show chassis hardware
Hardware inventory:
Item             Version  Part number  Serial number     Description
Chassis                                CZ3316AF0732      SRX345
Routing Engine   REV 0x07 650-065042   CZ3316AF0732      RE-SRX345
FPC 0                                                    FPC
  PIC 0                                                  8xGE,8xGE SFP Base PIC
    Xcvr 9       REV 01   740-031851   PTS26Q1           SFP-SX
Power Supply 0 
 
[edit]
root@SRX345-2# run show interfaces ge-0/0/9             
Physical interface: ge-0/0/9, Enabled, Physical link is Down
  Interface index: 145, SNMP ifIndex: 523
  Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Link-mode: Full-duplex,
  Speed: 1000mbps, BPDU Error: None, MAC-REWRITE Error: None,
  Loopback: Disabled, Source filtering: Disabled, Flow control: Disabled,
  Auto-negotiation: Enabled, Remote fault: Online
  Device flags   : Present Running Down
  Interface flags: Hardware-Down SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 30:b6:4f:2e:4d:ca, Hardware address: 30:b6:4f:2e:4d:ca
  Last flapped   : 2018-06-27 08:06:52 UTC (00:01:55 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : LINK
  Active defects : LINK
  Interface transmit statistics: Disabled
 

On QFX5110

 {master:0}[edit]
root# run show interfaces terse
Interface               Admin Link Proto    Local                 Remote
ge-0/0/0                up    down
ge-0/0/0.0              up    down inet     2.2.2.254/24   
gr-0/0/0                up    up
pfe-0/0/0               up    up
pfe-0/0/0.16383         up    up   inet   
                                   inet6  
pfh-0/0/0               up    up
pfh-0/0/0.16383         up    up   inet   
pfh-0/0/0.16384         up    up   inet   
xe-0/0/4                up    down
xe-0/0/4.0              up    down inet   
ge-0/0/10               up    up
ge-0/0/10.0             up    up   inet   
ge-0/0/30               up    down
ge-0/0/30.0             up    down inet     1.1.1.12/24    
ge-0/0/31               up    down
ge-0/0/31.0             up    down inet     1.1.1.1/24     
bme0                    up    up
bme0.0                  up    up   inet     128.0.0.1/2    
                                            128.0.0.4/2    
                                            128.0.0.16/2   
                                            128.0.0.63/2   
---(more)---[abort]
 
{master:0}[edit]
root# run show interfaces ge-0/0/10
Physical interface: ge-0/0/10, Enabled, Physical link is Up
  Interface index: 657, SNMP ifIndex: 638
  Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Speed: 1000mbps,
  BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None,
  Source filtering: Disabled
  Ethernet-Switching Error: None, MAC-REWRITE Error: None, Loopback: Disabled,
  Flow control: Disabled, Auto-negotiation: Disabled, Remote fault: Online,
  Media type: Fiber
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x4000
  Link flags     : None
  CoS queues     : 12 supported, 12 maximum usable queues
  Current address: 5c:45:27:9e:5f:cd, Hardware address: 5c:45:27:9e:5f:cd
  Last flapped   : 2018-06-27 08:03:51 UTC (00:04:12 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  PCS statistics                      Seconds
    Bit errors                             0
    Errored blocks                         0
  Ethernet FEC statistics              Errors
    FEC Corrected Errors                    0
    FEC Uncorrected Errors                  0
    FEC Corrected Errors Rate               0
    FEC Uncorrected Errors Rate             0
  Interface transmit statistics: Disabled
……

Solution

Link negotiation is enabled by default  on Gigabit Ethernet ports, link negotiation exchange flow-control parameters, remote fault information, and duplex information. The ports on both ends of a link must have the same setting. The link will not come up if the ports at each end of the link are set inconsistently (link negotiation enabled on one port and disabled on the other port).

By default, SRX enabled negotiation and QFX5110 disabled the negotiation. Therefore, the link of SRX is down and QFX is up as shown above.
Disable negotiation on SRX or enable negotiation on QFX to fix the issue, but to not change on both sides.

After running the following command on SRX, the issue could be resolved.

root@SRX345-2#set interfaces ge-0/0/9 gigether-options no-auto-negotiation
root@SRX345-2# commit
 
[edit]
root@SRX345-2# run show interfaces terse
Interface               Admin Link Proto    Local                 Remote
ge-0/0/0                up    down
……
ge-0/0/9                up    up
……
vtep                    up    up
 
[edit]
root@SRX345-2# run show interfaces ge-0/0/9
Physical interface: ge-0/0/9, Enabled, Physical link is Up
  Interface index: 145, SNMP ifIndex: 523
  Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Link-mode: Full-duplex,
  Speed: 1000mbps, BPDU Error: None, MAC-REWRITE Error: None,
  Loopback: Disabled, Source filtering: Disabled, Flow control: Disabled,
  Auto-negotiation: Disabled, Remote fault: Online
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Link flags     : None
  CoS queues     : 8 supported, 8 maximum usable queues
  Current address: 30:b6:4f:2e:4d:ca, Hardware address: 30:b6:4f:2e:4d:ca
  Last flapped   : 2018-06-27 08:10:02 UTC (00:03:06 ago)
  Input rate     : 0 bps (0 pps)
  Output rate    : 0 bps (0 pps)
  Active alarms  : None
  Active defects : None
  Interface transmit statistics: Disable

Modification History

2023-12-06: KB article is valid and accurate.