Flow Statistics on a CSS11150

[yves.haemmerli]

Hi,

In a corporate data center, I would like to have some figure on the current amount of traffic flowing through the CSS. Having studied technical information regarding fastpath FCBs, slowpath and Flow Manager FCBs I try to interpret the values given by flow commands in debug mode.

More specifically, in a real CSS, the debug command "flow statistics" gives me the following Flow manager values :

- Number of Allocated Flows (non-purged) 562

- Current Number of Active Flows 159325

- The summaty table gives :

----------------------------------------------------

Port Active Total Acct TCP

----------------------------------------------------

#e13-101 21 3491356 3538157 21

#e14 159290 27869406 27869167 159290

#e13-102 12 3834293 3991006 12

My interpretation is that the allocated flows (562)

are real flows (fastpath cache flows) ? If yes, what

does mean the "current number of active flows" and

the number displayed in the summary table (159290) ?

Second question is : is there an OID I could use to

monitor the number of active flows ?

Yves Haemmerli

[Gilles Dufour]

number of allocated flows is the number of FCB being used in software.

current number of active flows, is the number of FCB used in hardware [this is the sum of FCB used per interface - more or less].

Normally, the FCB used in software and hardware should match as the CSS keeps a copy of the hardware FCB in software.

Strange that these numbers are not the same for you.

For the mib, check flowmgrext.mib.

apFlowMgrStatIfFcbCount,apFlowMgrStatIfTCPCur,...

Regards,

Gilles.

[yves.haemmerli]

Hi Gilles,

Thank you for your answer. However I am a little bit confused because if the active flow counter indicates the number of FCBs in hardware, 159'325 is far above the 565 TCP flows indicated by the "flow active-list" command...and I ask me where this difference comes from ? As I am auditing my customer CSS, I would like to be able to explain this figure or maybe open a TAC case is necessary.

Could you please look at the attached file, which shows the output of the following commands in debug mode :

- flow statistics

- flow detail

- flow port

- flow active-list

Thank you for your support

Yves

[Gilles Dufour]

Yves,

the numbers reported for FCB at hardware level seems to be corrupted.

Normally, the active FCB in hardware should match more or less the FCB in software - so around 500.

Also the number of active fcb should be [more or less] the "total" number of FCB used minus the "Acct" number of FCB released.

So e14 should give a value like 239.

The number you see is way to high for e14.

I would suggest to open a case so we can track this down.

Gilles.

[Gilles Dufour]

Yves,

after talking with developpers, we believe the problem is the following bug CSCef38127.

Fixed in 6.10(4.05).

The bug actually mentions that in some conditions the active flow counter may ony increment and reach impossible value.

This is what you see on your e14 interface.

Regards,

Gilles.

[yves.haemmerli]

Hi Gilles,

Excellent, thank you for your information. We will upgrade the code. I was important for us to have the correct value as we are monitoring the actual number of flows of our CSS in our corporate Data Centers.

Thanks again

Yves