New Equipment Using Old IP

Our ISP recently swapped out about 60 of our site routers as we moved to metro fiber recently. These new routers have the same IP address (and system name) as the old routers. We have tried one by one to monitor the interfaces on these new routers, but if you bring up a node in Orion it shows the old interfaces, which obviously aren't there any more.

We can't seem to find a way to make Orion remove the old interfaces - we can't manually remove them, since the interfaces were on the old hardware and now aren't in the resources list. Is the only option at this point to delete the nodes and add the old hardware?

I tried to do some searches for this, because I figure something similar has been asked and answere before, but I must have had my search terms off a little. I'm running Orion 9.5 SP4 BTW. Thanks for any input.

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Accepted answers

mleinio

That's correct, the web console of NPM has a bug that makes the "List Resources" function to show incorrectly selected interfaces. This is a common problem for us as well, thanks for starting the discussion :-)

Let me give an example:

I first have a Cisco 837 router with Ethernet0 interface being monitored in NPM.

Then the service provider changes the router to Cisco 1841.

Now, NPM shows the Ethernet0 interface as unknown. This is correct as Cisco 1841 does not have the Ethernet0 interface at all.

However, if I go to List Resources, NPM shows all the currently available interfaces, and shows FastEthernet3 (or some other existing interface) as being monitored! This is not correct, the statistics for FastEthernet3 is not being collected, it just doesn't work.

The fix is (as Miron said) to delete the "unknown" interface in the Manage Nodes view, and then to go again to List Resources and select the necessary interfaces. (If I remember correctly just removing the checkmark in the List Resources view does not delete the interface, but I may remember it wrong now.)

I think this kind of problem did not exist in the System Manager (the GUI application), it was able to differentiate between existing and nonexisting interfaces.

Maybe the web console application maps the ifindexes somehow incorrectly or something else. In addition to using the SNMP ifindex to find the interface I think the application should also check that the interface name/type matches the previous information in the database. If it does not match, then NPM should know that now the interface does not match anymore. You got the idea I think.

Markku

All comments

mcbridea

Have you tried to rediscover those nodes?

acherman

I have had similar issues - replace a Cisco switch with an Extreme switch, etc. Generally what I do is delete the old interfaces that show unknown status, rediscover, and then list resources again.

MNPS_G

I just manually added the node again to try and see what would happen. When it came to the interfaces, it already had the new ones checked, and our custom fields were filled out appropriately. I think that should be equivalent to doing the discovery you mentioned.

However, the old interfaces are the only ones listed. Orion is getting the correct device information, because the machine type and description both fit the new router. It is just holding onto the old interface information.

Miron

Hi,

The interfaces will still exist even though they no longer show up as a resource on the new node which is expected.

Through the admin console go to the manage nodes and change from nodes to interfaces, if these interfaces have a name in common refine your search to those. You will see all the old interfaces as grey(unknown) simply select them all and delete them.

Job done

Miron

MNPS_G

Hi,
The interfaces will still exist even though they no longer show up as a resource on the new node which is expected.
Through the admin console go to the manage nodes and change from nodes to interfaces, if these interfaces have a name in common refine your search to those. You will see all the old interfaces as grey(unknown) simply select them all and delete them.
Job done
Miron

Miron,

I'll try that in a bit. However, the node still isn't showing the interfaces on the new switch, even though they are checked under the 'List Resources' page for that node. I don't quite understand why they're not shown.

Thanks for the help though, I'll let you know how the delete works, but it makes complete sense and wish I had thought of it earlier.

Geoffrey