We are running a Juniper MX480 router is a production environment. Due to increase in traffic trend , it was required to installed new FPC 'MPC-3D-16XGE-SFPP' into slot 5 of MX480. Before the addition , below was the status of 4 x FPCs installed.
user@Juniper-MX480-BB1> show chassis fpc
Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%)
Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer
0 Online 46 24 1 23 23 23 2048 24 24
1 Online 50 33 3 34 35 35 2048 38 39
2 Online 47 24 0 22 22 22 2048 23 23
3 Empty
4 Online 47 22 1 22 22 21 2048 26 22
However , when the FPC was installed in slot 5 chassis alarm with severity 'Major' appeared.
user@Juniper-MX480-BB1> show chassis alarms
1 alarms currently active
Alarm time Class Description
2021-03-13 03:07:20 PKT Major CB fabric links require upgrade/training
This alarm showed for some time and then vanished.The new FPC in slot 5 also went online.
user@Juniper-MX480-BB1> show chassis fpc
Temp CPU Utilization (%) CPU Utilization (%) Memory Utilization (%)
Slot State (C) Total Interrupt 1min 5min 15min DRAM (MB) Heap Buffer
0 Online 46 23 1 23 22 22 2048 24 24
1 Online 50 35 3 36 35 35 2048 38 39
2 Online 48 24 0 23 23 22 2048 23 23
3 Empty
4 Online 47 22 1 25 22 22 2048 26 22
5 Online 48 23 0 22 24 24 2048 27 21
Need to understand why this alarm appeared when Juniper MX480 supports 6 x FPCs and there is a vacant position for one more FPC in slot position 3.
Does it have something to do with 'fabric'. If so , how? We are currently running MX480 in redundant Fabric Mode.
Do we need to change the mode from redundant to increased bandwidth mode? Is it mandatory?
Since the FPC is online , what are the implications if we don't change the Fabric Mode?
user@Juniper-MX480-BB1> show chassis fabric redundancy-mode
Fabric redundancy mode: Redundant Fabric
user@Juniper-MX480-BB1> show chassis fabric summary
Plane State Uptime
0 Online 3 days, 11 hours, 9 minutes, 19 seconds
1 Online 3 days, 11 hours, 9 minutes, 19 seconds
2 Online 3 days, 11 hours, 9 minutes, 12 seconds
3 Online 3 days, 11 hours, 9 minutes, 12 seconds
4 Spare 3 days, 11 hours, 9 minutes, 6 seconds
5 Spare 3 days, 11 hours, 9 minutes, 5 seconds
6 Spare 3 days, 11 hours, 8 minutes, 59 seconds
7 Spare 3 days, 11 hours, 8 minutes, 59 seconds
Chassis Hardware
user@Juniper-MX480-BB1> show chassis hardware clei-models
Hardware inventory:
Item Version Part number CLEI code FRU model number
Midplane REV 05 710-017414 CHAS-BP-MX480-S
FPM Board REV 02 710-017254 CRAFT-MX480-S
PEM 0 Rev 05 740-027736 PWR-MX480-2400-DC-S
PEM 1 Rev 05 740-027736 PWR-MX480-2400-DC-S
PEM 2 Rev 05 740-027736 PWR-MX480-2400-DC-S
PEM 3 Rev 05 740-027736 PWR-MX480-2400-DC-S
Routing Engine 0 REV 07 740-031116 COUCALDBAB RE-S-1800X4-16G-S
Routing Engine 1 REV 07 740-031116 COUCALDBAB RE-S-1800X4-16G-S
CB 0 REV 14 750-031391 COUCARCBAA SCBE-MX-S
CB 1 REV 15 750-031391 COUCARCBAA SCBE-MX-S
FPC 0 REV 24 750-031088 COUIBBEBAB MX-MPC2-3D-Q
MIC 0 REV 26 750-028392 COUIA15BAA MIC-3D-20GE-SFP
MIC 1 REV 26 750-028392 COUIA15BAA MIC-3D-20GE-SFP
FPC 1 REV 24 750-031088 COUIBBEBAB MX-MPC2-3D-Q
MIC 0 REV 28 750-028387 COUIA16BAA MIC-3D-4XGE-XFP
MIC 1 REV 26 750-028392 COUIA15BAA MIC-3D-20GE-SFP
FPC 2 REV 26 750-031089 COUIBBDBAB MX-MPC2-3D
MIC 0 REV 28 750-028387 COUIA16BAA MIC-3D-4XGE-XFP
MIC 1 REV 31 750-028387 COUIA16BAB MIC-3D-4XGE-XFP
FPC 4 REV 15 750-031088 COUIA18BAA MX-MPC2-3D-Q
MIC 1 REV 31 750-028387 COUIA16BAB MIC-3D-4XGE-XFP
FPC 5 REV 38 750-028467 MPC-3D-16XGE-SFPP
Fan Tray FFANTRAY-MX480-HC-S
I would be thankful if someone could explain this with details.