Description

SRX345 cluster is connected to another vendor switch, the switch shows the interface as UP, but on SRX side it is shown as DOWN.

Symptoms

We can observe that physical link on SRX345 is down, however, optical signal is received: 
 {primary:node0}
 user@srx345> show interfaces ge-0/0/9 extensive
 Physical interface: ge-0/0/9, Enabled, Physical link is Down
   Interface index: 175, SNMP ifIndex: 524, Generation: 196
...

user@srx> show interfaces diagnostics optics ge-0/0/9
Physical interface: ge-0/0/9
    Laser bias current                        :  3.972 mA
    Laser output power                        :  0.2720 mW / -5.65 dBm
    Module temperature                        :  29 degrees C / 84 degrees F
    Module voltage                            :  3.3820 V
    Laser receiver power                      :  0.1128 mW / -9.48 dBm
...

Solution

SRX should be configured with no-auto-negotiation, speed set to 1g and link-mode to full-duplex:

user@srx> show configuration interfaces ge-0/0/9
speed 1g;
link-mode full-duplex;
ether-options {
    no-auto-negotiation;
}
...

After this configuration is added, the link comes up:

 {primary:node0}
 user@srx345> show interfaces ge-0/0/9 extensive
 Physical interface: ge-0/0/9, Enabled, Physical link is Up
   Interface index: 175, SNMP ifIndex: 524, Generation: 196
...


The switch port where SRX is connected to must be configured with no-auto-negotiation too. Otherwise, the link on SRX might still be shown as Down.

Modification History

2024-02-27 : Article Created