Junos OS

I have 2 boxes MX960 and MX480 with 2 RE respectively. 

Both SCB cards' (Master and Backup) Fabric active are on (Green colors) on MX960

But MX480, why the Fabric Active LED light is only on at master SCB  while the Backup unit is off?

show chassis environment cb, it shown that Master unit is online active while backup is online standby. 

 ( The OK/FAIL LED is green color )

Does anyone know why the Fabric active light is off while the SCB card and RE already in backup mode.

Is it suppose to behave like this ?

or the LED light is faulty?

Why it's not behave same as MX 960 ?

Is MX960 and MX480 has difference in hardware architecture?

Hi,

the architecture of both MX-series are the same.

However, the MX960 has 2 + 1 SCB redundancy, whilst the MX480 has 1 + 1.

So if both of them are having 2 SCBs, the second will be active for the MX960, but redundant for the MX480.

I hope this helps.

Cheers,

Bruno 

Hi Bruno

For clarification,

Since MX 480 is 1+1 redunduncy, does it mean the Fabric active LED light only will be on (Green) at "Online Master" unit?

b'coz the cb status in MX 480 are "Online Master" and "Online Standby" exactly same as MX960 but both Fabric active LED light is on at both CB of MX 960 and MX 480 Fabric active only On at "Online Master" unit.

Hi,

yes that is correct. The second SCB on MX480 is not activated, although it can obviously be installed and on-line. But ir will not do any active switching of packets, unless the master fails.

you can have a look at http://www.juniper.net/techpubs/en_US/release-independent/junos/topics/reference/general/scb-mx480-leds.html for confirmation.

Cheers,

Bruno