Switching

Hi,

I am planning to test EX3200 for the throuput/scalability. I am sending across 6G of traffic. It looks like the CPU utlizaition didn't go very high (using show chassis routing-engine command) but the ports traffic stats that they are dropping lot of packets. Is there a way to check the forwarding plane stats on EX3200?

Thanks

Is there any equivalent command of "show security monitoring fpc 0" availalbe for EX3200 in order to check the PEF

There is a wealth of information available under the "show pfe" command that is likely what you are looking for.  That said, I really think that there must be something misconfigured as the EX3200 should be able to handle much more that 6GB of traffic.  The 24-port models are rated for 88Gbps / 65Mpps and the 48-port models for 136Gbps / 101Mpps.

Ron

How are you sending traffic across?

Easy way to test throughput on a single chassis is just to use a bunch of ethernet cables, and loop traffic from port to port using different vlans. So that way you turn a 1Gb flow into 15Gb or however much you want to test.

EX3200 should do way more than 6Gb. 

I am using a traffic generator to send the traffic across.

In SRX, "show security monitoring fpc 0 " provide a very clean view of CPU and mem utilization by forwarding plance. I am unable to find such command for EX3200

FPC 0
  PIC 0
    CPU utilization      :  100 %
    Memory utilization   :   46 %
    Current flow session :    1
    Max flow session     : 16384

In a EX chassis, traffic never hits the CPU as it is handled by the ASICs.

The CPU is used for various protocols, MST,OSPF, BFD and such.  I am trying to see of there is anything that can detail backplane performance.

edit: Do you show anything odd under : show pfe statistics traffic

edit2: You can always try to login to the PFE from shell and see what you can find there.

You mentioned using a traffic generator.  If you fiddled with the packet gap settings for the rate put it back to the default of 12 byte minimum gap.  That's the interframe gap and 12 bytes is the minimum required per ethernet spec.  If you set the gap lower then the traffic doesn't meet spec and will be dropped as an error.

I mention it because I did exactly that, figuring a lower gap would stress the system more.  I spent a while trying to figure out why a very low traffic load was getting loss.  Thankfully I had a few different traffic flows running.  All of the others were perfectly clean while just one was dirty.  Helped point out the fact that I messed up the test configuration.

-Chad

Thanks Michael and Chad for the reply.  Yes is notice small traffic loss when using a small size packet.

I am not very familier with Junos and EX3200 so please bear with my ignorance. I am more interested to check the load on PFE during traffic blast  rather than interface stats. SRX has that command (show security monitoring fpc 0) to show the load during packet forwarding but somehow if couldn't find the equivalent for EX3200.

The SRX uses CPUs to forward traffic via software. For every packet flow, the SRX has to analyize TCP state/ NAT/ACL/etc. Some are executed in hardware I assume, but some features will require the use of the CPU.

The EX3200 uses the CPU to calculate the forwarding path, and then pushes that forwarding information down to the ASIC level. The CPU has no involvement in forwarding traffic itself. the EX3200/4200/4500 can be heavily utilized but the CPU will be nearly idle.  My core network is a pair of 4200s (soon to be 4500s) and the CPU graph never moves based on traffic load, even during backup nights. 

The command that gives information on what is passing through the PFE is "show pfe statistics traffic", however it doesn't provide any information for the EX at the moment.  There is an enhancement request in to get that functionality.

There are a few others that will give some information:

show chassis routing-engine:  will give info on how long the RE has been up, RE serial number, CPU load broken down by type, temperature, and load average.

show chassis fpc:  gives CPU and memory information about each FPC (line card / node).

show system uptime:  shows the current time, boot time, and load average for each FPC

On the EX3200, the best one to use is the first one.  The other two will work but are more applicable for other systems like the EX3300 and EX4200 when running virtual chassis and the chassis-based EX6200 and EX8200 with independent routing engines..  

For global traffic statistics though, show pfe will eventually be the one to go to.  If you just want to see what is happening on the interfaces then  monitor interface <interface> and monitor interface traffic are your friends.

Thanks Guys.........I was using show chassis routing-engine . I guess that's the best so for in EX.