When I replace a (usually Cisco) switch (same name and address), I rediscover it in Orion and choose the ports I now want to monitor. Usually, the old switch is a C2960 100mb model, the new switch does not have any 100mb ports. This does not work for UDT. When I look at the node, one of the widgets displayed is the list of (UDT) monitored ports. It continues to display 100mb ports (i.e. Fa0/1, Fa0/2) that no longer exist. Short of deleting / readding the node, I don't know how I can clean it up.
You've stumbled onto one of several items for which Feature Requests have been submitted. Even as @Kaellanon said, the only complete and satisfactory solution I've found is to delete the node entirely from Solarwinds and then re-add it.
If you're willing to give the replacement switch a new IP address and node name, that should also provide a proper new discovery, after which you can copy the configs off the NPM/NCM records for the old switch, and then delete the old switch from Solarwinds.
If you don't follow this process you'll end up with an increasing number of nodes with "Unknown Interface" issues. There's just no deleting them, or using the "Discover Resources" or Rediscover options to get those invalid interfaces out of your database. The only solution I've found is deleting the old node entirely and then adding its replacement.
I had the same issue when replacing switches. The only solution I found was to delete the switch and let network discovery pick it up again. I will then re-add it and it has all the correct parameters.
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