How to use the FPC shell commands to check interface buffer size for each queue in the MX304 platform.
{master}
labroot@BNGR-1> show version
Hostname: BNGR-1
Model: mx304
Junos: 23.2R2.21 <<<<<< different Junos OS may have various results.
JUNOS OS Kernel 64-bit [20240103.68b4802_builder_stable_12_232]
labroot@BNGR-1> show interfaces et-0/0/5
Physical interface: et-0/0/5, Enabled, Physical link is Up
Interface index: 235, SNMP ifIndex: 541 <<<<< index is 235, will be used later
labroot@BNGR-1> start shell pfe network fpc0 <<<<< login FPC0, please only run show command
root@BNGR-1-fpc0:pfe> show class-of-service interface scheduler hierarchy index 235
Interface Schedulers:
Name Type Index Level Node-Token Shaping-Rate Guaranteed-Rate Delay-Buffer-Rate Excess-Rate
et-0/0/5 IFD 235 1 3445 100000000000 100000000000 100000000000 1 <<<<< token is 3445
root@BNGR-1-fpc0:pfe> show sandbox token 3445
AftNode : bindMask:0x2AftCosSched token:3445 group:2 tag:schedNode(cos) TagIndex:535 nodeMask:0x2
DebugTxt:NA
ParentToken:NA
SchedMapToken:2576
ScaleFactor:1
StreamToken:3389
MaxLevels:1
Level:0
Enable:1
SchedMode:Nominal
OverheadAcct:24
CellMode:0
dbbTimeU:0.00 seconds
GlobalBaseId:0
SchedNodeType:2
Node Index:235
Node Name:et-0/0/5
Parent Name:
QMonEnable:0
Interface Rate:100.00Gbps
DelayBufferRate:100.00Gbps
Table: CoS Scheduler AFT Node
-------------------------------------------
Rate | Priority | Rate | Burst |
Type | Group | (bps) | Size (B}|
----------+-----------+---------+---------+
Guaranteed| Nominal| 100.0G| 32.8K|
Excess| Nominal| 1.0| 1.0|
Excess| StrictHigh| 1.0| 1.0|
Excess| High| 1.0| 1.0|
Excess| Med High| 1.0| 1.0|
Excess| Med Low| 1.0| 1.0|
Excess| Low| 1.0| 1.0|
Maximum| Nominal| 100.0G| 1.2G|
Maximum| StrictHigh| 0.0| 0.0|
Maximum| High| 0.0| 0.0|
Maximum| Med High| 0.0| 0.0|
Maximum| Med Low| 0.0| 0.0|
Maximum| Low| 0.0| 0.0|
JnhHandle : JnhHandleCosSchedNode Jnh:0x0 PfeInst:1 Paddr:0x0 Vaddr:0x0 JnhDecodeAllowed:Yes
CoS Scheduler Node:
PFE Instance : 1 <<<<<<<<< this interface connects to ASIC 1
L1 Index : 34
L2 Index : 457
L3 Index : 969
L4 Index : 10 <<<<<<<< e.g. L4 index is 10
Enhanced Priority Mode : 0
Table: Queue Configuration
------------------------------------------------------------------------------------------------------------
Index | Shaping-Rate | Transmit-Rate | Burst | Weight | G-Priority | E-Priority | Tail-Rule | WRED-Rule |
--------+--------------+---------------+--------+--------+------------+------------+-----------+-----------+
80 | 100.0G | 95.0G | 1.2G | 95 | GL | EL | 1424 | 0 | <<<<< for Q0, tail-rule is 1424
81 | 100.0G | 0.0 | 1.2G | 1 | GL | EL | 279 | 0 |
82 | 100.0G | 0.0 | 1.2G | 1 | GL | EL | 279 | 0 |
83 | 100.0G | 5.0G | 1.2G | 5 | GL | EL | 1087 | 0 |
84 | 100.0G | 0.0 | 1.2G | 1 | GL | EL | 279 | 0 |
85 | 100.0G | 0.0 | 1.2G | 1 | GL | EL | 279 | 0 |
86 | 100.0G | 0.0 | 1.2G | 1 | GL | EL | 279 | 0 |
87 | 100.0G | 0.0 | 1.2G | 1 | GL | EL | 279 | 0 | <<<<< Q7, sequenced
Queue Statistics:
PFE Instance : 1
Transmitted Dropped
Bytes Packets Bytes Packets
---------------------------------------------------------------------------------------------------------------------------------------
Queue:0 17782344( 0 bps) 119022( 0 pps) 0( 0 bps) 0( 0 pps)
Queue:1 0( 0 bps) 0( 0 pps) 0( 0 bps) 0( 0 pps)
Queue:2 0( 0 bps) 0( 0 pps) 0( 0 bps) 0( 0 pps)
Queue:3 29537339( 1048 bps) 143419( 2 pps) 0( 0 bps) 0( 0 pps)
Queue:4 0( 0 bps) 0( 0 pps) 0( 0 bps) 0( 0 pps)
Queue:5 0( 0 bps) 0( 0 pps) 0( 0 bps) 0( 0 pps)
Queue:6 0( 0 bps) 0( 0 pps) 0( 0 bps) 0( 0 pps)
Queue:7 0( 0 bps) 0( 0 pps) 0( 0 bps) 0( 0 pps)
Previous nodes count: 24
Next nodes count : 2
Entries count : 0
root@BNGR-1-fpc0:pfe> show cda xqss drop tail-drop-rule 1 rule 1424 <<<<< ASIC 1, tail-rule is 1424 for et-0/0/5 queue 0
Qchip : 1
Index : 1424
Reference Count : 8
Threshold Bytes Mantissa Shift
--------------- ------------- -------
1191182336 142 23 <<<<<< buffer size is 1191182336 bytes, reach this value, tail-drop starts. NOTE, WRED drop may trigger earlier.