unknown interface status

Which version are you running?  I recall that I had a similar issue in 8.5, I believe, but it was fixed in a service pack.

i am running 9.1 SP5

Hmm...I doubt it's the same problem, then.  I assume the devices are all reachable during the time the interfaces become "unknown"?  Does SNMP respond during this time?

yes they are pingable by their ip but if i try to list teh resources it times out.

Are all the nodes that are having this problem all behind a certain device?  When they all go into "unknown" status, does it happen to all devices at the same time?  Would it be possible to use a free SNMP walk tool and install it on one of the servers to see if you can walk the SNMP tree locally? 

If it's not an upstream device that's stopping the SNMP communication, then it would likely be the devices themselves.  However, if they are all stopping at the same time, that would lead me to believe that the problem is with something like a firewall stopping the SNMP communication, perhaps some type of application or protocol throttling being done (IDS/IPS, perhaps?).

all of the servers are in the same location (except for a few, but i never have problems with those) I don't think the server guys would appretiate me installing something since the nodes with the issue are our exchange servers and they are relaly careful with those. How ever my polling server is in the same location. I could run mib walk (we have the SW engineers toolset). One other thing is that alot of our interfaces are HP Teams, would this be causing an issue as well since their virtual.

So are all the interfaces that go unknown this type?  I can say that I've occasionally had some strange problems getting virtual interfaces to show up on some boxes.  I have a couple of virtual servers that I can do a "List Resources" on and see the interfaces, but when polling them, they never come out of "Unknown" status.

I'd try using MIB walk or the SNMP MIB Browser to poll the IF-MIB table while the problem is happening.  It doesn't sound like a problem with Orion, given the description, but you never know.

I am experiencing this as well.  We are running NPM 9.1 SP5 as well.  Currently we are seeing this with VM servers as well as Cisco Call Mangager servers.

i was seeing this as well with our vmware servers. But some of thoses were dns related and seem to be fine now. So for me it's just physical servers with he virtual teamed nics.

In that case, if you can pull up the Interfaces table with the SNMP MIB Viewer tool while the problem is happening, but you cannot poll or list resources with Orion, then I'd say it's an Orion issue and you'll probably want to open a ticket.  Otherwise, I'd say that it's an issue with the servers.  Good luck and please post any results.