sFLOW Configuration on PC 6248

Question

The performance of some of my backups decresed after I added an extra switch to my 4 switch stack and updated the PC6248 firmware to 3.3.2.3. I would like to get some performance information from the switch and I am not quite sure how to acomplish this. I was told that sFLOW is the way to go.

Can someone post some instructions/best practices on how to configure sFlow on the 6248 using CLI?

netvis · Answer

Here are some configuration instructions:

http://blog.sflow.com/2010/02/configuring-dell-switches.html

and here is an example of how to use sFlow to analyze network performance:

http://blog.sflow.com/2011/06/five-ws.html

ThiloWunderlich · Answer

No, it won't reset the stack.

If you need a free sflow program, try this:

www.inmon.com/.../sFlowTrend.php

Be ware that there seems to be a bug in the Dell Sflow Code, you have to use a BIG timeout!

this is what I use:

sflow 1 destination owner 1 timeout 4292702568

sflow 1 destination

interface ethernet 1/g48

sflow 1 polling 60

exit

Thilo

BAI-JD · Answer

Do you know if it can be configured without causing down time?  I need to start using it asap but I don't know if it's going to reset any of the interfaces on the switch.

BAI-JD · Answer

Thanks a lot for your help.

Is there a limit in the amount of ports I can monitor?

I have 5 6248 switches on a stack. If I monitor all ports could that cause perfomance issues on the network?

Should I exclude the receiver port?

How do you decide what sample size to use?

netvis · Answer

The following article discusses the choice of sampling rates:

http://blog.sflow.com/2009/06/sampling-rates.html

It does seem like there may be a limit on the number of interfaces you can sample in a stacked configuration:

http://en.community.dell.com/support-forums/network-switches/f/866/p/19358912/19798430.aspx

Networking General

sFLOW Configuration on PC 6248

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