Ethernet Switching
Ethernet Switching

monitor interface data units

2 weeks ago

Hello !

 

I was trying to monitor traffic on some link on a qfx5110-32q switch with monitor interface command.

Exemple : 

Interface: et-0/0/0, Enabled, Link is Up
Encapsulation: Ethernet, Speed: 40000mbps
Traffic statistics: Current delta
Input bytes: 4952140865259937 (9161687480 bps) [33005609474]

Output bytes: 1276782093570122 (1990947864 bps) [8964820590]

 

Documentation tells that bps=bytes per second (and i know bps is,instead usually related to bit per second). But you see above that 9.16G bytes per second is not possible on a 40Gbps link.

Unit error in documentation or i missed something ?

 

a nice day to all !

 

4 REPLIES 4
Ethernet Switching

Re: monitor interface data units

2 weeks ago

Hi,

 

bps in the output you have shared absolutely refers to bits per second and is the result of the command "monitor traffic <interface-name>".

 

If some documentation refers to bps in this output, then it can be an error. Can you share any such documentation if found.

 

However, when you run the command "monitor traffic interface" which shows the output for all the interfaces, initially it shows in pps. When you press b on the go, the stats start showing in bps and here it is bytes per second.

 

Ex:

 

 

Bytes=b, Clear=c, Delta=d, Packets=p, Quit=q or ESC, Rate=r, Up=^U, Down=^D
jtac-qfx10008-r2014-

Interface    Link  Input packets        (pps)     Output packets        (pps)
 xe-0/0/0:2    Up     1166375332    (3272224)        645377333          (0)

Now, press b:

 

Bytes=b, Clear=c, Delta=d, Packets=p, Quit=q or ESC, Rate=r, Up=^U, Down=^D
jtac-qfx10008-r2014-              Seconds: 12                  Time: 23:56:10

Interface    Link     Input bytes        (bps)      Output bytes        (bps)
 xe-0/0/0:2    Up    437454431342 (9477367488)      233519437573       (1016)

Hope this helps.

 

Thanks and Regards,

Pradeep Kumar M

 

 

Ethernet Switching

Re: monitor interface data units

2 weeks ago

Hi,

Can you please share the documentation URL? You're probably misinterpreting it.

9161 Mbps = 1145.125 MB/s



If this worked for you please flag my post as an "Accepted Solution" so others can benefit.
Ethernet Switching

Re: monitor interface data units

[ Edited ]
a week ago

Hello, thanks for your assistance : )

 

My initial post was blurry. A better version : 

bps value for ae0 interface via "monitor interface traffic'' command is (very much around) the same as bps value via "monitor interface ae0".

Documentation (https://www.juniper.net/documentation/en_US/junos/topics/task/operational/security-real-time-interfa...) shows : 

Table 1: CLI monitor interface Output Control Keys

Key

Action

c

Clears (returns to 0) the delta counters in the Current delta column. The statistics counters are not cleared.

f

Freezes the display, halting the update of the statistics and delta counters.

i

Displays information about a different interface. You are prompted for the name of a specific interface.

n

Displays information about the next interface. The device scrolls through the physical and logical interfaces in the same order in which they are displayed by the show interfaces terse command.

q or ESC

Quits the command and returns to the command prompt.

t

Thaws the display, resuming the update of the statistics and delta counters.

Table 2: CLI monitor interface traffic Output Control Keys

Key

Action

b

Displays the statistics in units of bytes and bytes per second (bps).

c

Clears (returns to 0) the delta counters in the Delta column. The statistics counters are not cleared.

d

Displays the Delta column instead of the rate column—in bps or packets per second (pps).

p

Displays the statistics in units of packets and packets per second (pps).

q or ESC

Quits the command and returns to the command prompt.

r

Displays the rate column—in bps and pps—instead of the Delta column.

 

Bold text seems to be wrong as value returned by monitor interface traffic seems in bits.

 

''Input bytes'' returned by both commands  is therefore confusing now. If we assume that bps are bits per seconds.

Is there some way to display those values in human readable format ?

It could also be an idea to put a ''%bandwidth used'' somewhere, but perhaps i missed it as i am novice at JunOS. Trying to look into perormances issues i was looking at how much data was beeing trnsmitted over our 40Gb/s link.

 

A nice day to all !

Ethernet Switching

Re: monitor interface data units

a week ago

Actually, It is very easy to understand bit per second(bps) equal to how many gigabit/megabit per second in cli.

Firstly, I recommend examining the below URL(Table 1: PPS Calculation). It is showing "Speed vs bits/second"

https://kb.juniper.net/InfoCenter/index?page=content&id=KB14737

And then just use your cursor to divide pps numbers to slices. You will understand in couple of examples and also a few seconds.

Like > 

Bytes=b, Clear=c, Delta=d, Packets=p, Quit=q or ESC, Rate=r, Up=^U, Down=^D
jtac-qfx10008-r2014-              Seconds: 12                  Time: 23:56:10

Interface    Link     Input bytes        (bps)      Output bytes        (bps)
 xe-0/0/0:2    Up    437454431342 (9477367488)      233519437573       (1016)

 



If this worked for you please flag my post as an "Accepted Solution" so others can benefit.