DFM- thresholds for specific unique ports

Answered Question
Apr 10th, 2008

I'm looking to apply a threshold to one particular port on a single router and get the resulting alerts for that as well. I'm not sure what parameters to use though. Would this be done under Customizable Interface Groups and can I actually the use the port description or some keyword therein as the variable? It is probably the only unique thing about the port on that device.


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Correct Answer by Joe Clarke about 8 years 6 months ago

2% utilization on a 100 Mbps full-duplex port would equate to 2 Mbps sustained in one direction.

To remove group customization, edit the desired group's properties, and remove the ruleset. You should apply changes after doing so.

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js88888888 Thu, 04/10/2008 - 08:32

Also.... why can't we rename the Customizeable Groups? Hard coded read-only so DFM doesn't blow up? Seems like a delicate application, at least 2.0.10 does.

Joe Clarke Thu, 04/10/2008 - 15:27

Hard coded so DFM doesn't blow up is as good a reason as any. Due to the integration between the Cisco and the EMC pieces of DFM, it was easier to leave the group names static. However, their descriptions can be changed.

js88888888 Thu, 04/10/2008 - 12:31

OK, I'm trying to use a few attributes but am not sure which to use since DFM has its own little unique set of "naming".

I tried using the configured "description" in the port config under a few "name" properties in a custom interface group but that doesn't seem to be working.

DFM lists other attributes when I drill down to the interface;

Element Name - appears to be unique to the device

Display Name - definitely unique globally.

Description - Generic.....

Port Number- Not even sure where it gets this number but it doesn't correspond to the actual port number. I think these are unique within the device.

Are any of these fields usable for creating a custom interface group?

Joe Clarke Thu, 04/10/2008 - 15:35

Hopefully you're still using one of the Customizable Interface Groups, and you haven't created a new group. If so, and you want to group ONE interface on ONE router, the best ruleset to use is:

Interface.Name equals "NAME"

Where NAME is the Element Name for the interface as seen in the Detailed Device View. For example, I have a 7206 router with an interface called IF-nms-7206a.rtp.cisco.com/3. If I wanted to modify a group that matched only that interface, my ruleset would be:

Interface.Name equals "IF-nms-7206a.rtp.cisco.com/3"

Once the ruleset is good, you need to go to DFM > Configuration > Polling and Thresholds > Setting Priorities and float the modified group up to the top of Interface Threshold Groups. Then you need to Apply changes.

After doing those two steps, you should be able to go to DFM > Configuration > Polling and Thresholds > Managing Thresholds, find your modified customizable group, then click View. In the window that pops up, click View Interfaces, and you should see your matched interface.

Now you can adjust the thresholds as you desire.

js88888888 Fri, 04/11/2008 - 07:53

Thanks JC. I did that but the group doesn't show any applicable interfaces. I used the Element Name verbatim as the value then bumped that group up to the top for Interface Threshold Groups priorities. I'll double check, might have missed a space somewhere in the value string.

Joe Clarke Fri, 04/11/2008 - 07:57

You MUST go to DFM > Configuration > Polling and Thresholds > Apply Changes after changing your priorities. If you do not do that, your changes will have no effect.

js88888888 Fri, 04/11/2008 - 09:09

I have done that last step (apply changes)but its still showing empty.

Joe Clarke Fri, 04/11/2008 - 09:30

A set of screenshots would be helpful to see exactly what you've done so I can see if there are any obvious issues. I just tested this on another server, and it worked fine.

js88888888 Mon, 04/14/2008 - 09:40

Quick question just so I'm sure its not a simple syntax issue. Each of the ports on that router show an element name of "PORT-devicame.domain.com/x.x". I assume that "PORT" part is normal? Also, the Display Name shows the above line plus the configured description line in brackets. Would that be useful as variable?

And, what is the deal on that Port Number value? I'm not quite sure what logic is used but would that be unique? They are just 3 digit numericals (450, 504, etc) showing up in DFM Device Details.


js88888888 Mon, 04/14/2008 - 09:43

oh and, this is not a trunk port so would there be a need to configure this custom group under Access Port groups vs. Interface port groups?

Joe Clarke Mon, 04/14/2008 - 09:46

What type of device, and what is the name of the port/interface?

Joe Clarke Mon, 04/14/2008 - 09:47

It would be useful to see a screenshot. But since these are ports and not interfaces, you will have to configure the group under one of the customizable port groups. DFM considers trunk ports to be any switch port which connects to another managed device. All other ports are access ports.

js88888888 Mon, 04/14/2008 - 10:01

This a single 10/100 port on a 6509 which connects to our core router which is where all of our internet flows through. So since both of those devices are managed and it would then be considered a trunk port in DFM?

Joe Clarke Mon, 04/14/2008 - 10:02

If both devices are managed via DFM, then yes, it would be a trunk port. You can verify this by going to the same Manage Thresholds view for either trunk ports are access ports and see where this port is matched.

js88888888 Mon, 04/14/2008 - 10:19

OK, that was the ticket. Its port is now showing up under the new custom Trunk Port group. I set the metric very low for utilization, what would %2 utilization correllate to on a 100-full port?

Also, what is the best way to clean up/deactivate custom groups? I see if I remove the argument string it will not show up in Managing Thresholds. Is this best or is going into Edit-Customize Settings- and then removing the Active Settings better? I'm a bit cautious and would like to keep DFM's internals running clean.

thanks again!

js88888888 Mon, 04/14/2008 - 11:03

To clarify the utilization calculation. I want to set a threshold of 6Mbps (bits) on a 100-full port.

Would this calculate to 48,000,000/10,000,000,000 ?

6Mbps * 8/ 100,000,000Mbps * 100 ?

Joe Clarke Mon, 04/14/2008 - 13:32

Utilization percentage in one direction is calculated as the change in the octet counters over the time period multiplied times 8, divided by ifSpeed, multiplied times 100. So:

(octets2 - octets1) * 8

----------------------------- * 100

((time in seconds) * ifSpeed)

So, a 100 Mbps interface has an ifSpeed of 100000000. DFM usually polls in four minute intervals, so time is 240 seconds. If you want the utilization to be 6,000,000,000 bits per second in one direction, then your percentage will be 6%. 6% utilization would equate to a delta of 180,000,000 bytes between the first and second poll given a four minute polling interval.

Correct Answer
Joe Clarke Mon, 04/14/2008 - 12:54

2% utilization on a 100 Mbps full-duplex port would equate to 2 Mbps sustained in one direction.

To remove group customization, edit the desired group's properties, and remove the ruleset. You should apply changes after doing so.


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