Hi,
I'm by no way an expert on SIM, and don't claim to be!
However, I've been through the same document you've linked above, and managed to get (eventually) an amount of data pulled back from the Dell's.
I have the problem of supporting servers over ADSL WAN links, with no Domain Trusts - and I admit, I'm still struggling... however, the local Dell and HP Servers monitored by SIM chat quite happily to each other!
You have to add the MIB's in, as per the document you've mentioned above.
Then make sure SNMP is talking correctly - much easier on a LAN, or Company WAN than straight over the net.
1) SNMP must be running, and configured with a Community string that is reflected the same on ALL servers and the machine with SIM - SIM also have to have the same Community String: Options | Protocol Settings | Global Protocol Settings
Also you MAY have to have a read/write Community String - I'm a tad confused here - I think older versions needed read/write - but I've read mixed reports about whether 5 does or not (you certainly need Read though) - if you're servers are not directly on the net, and you have a good Firewall blocking outbound SNMP, then you'll be fine. If not, test it with both - and as always, finish with the most secure way that works!
Also, set SNMP to receive from 'Any Host' to start with - basically, get it going, then start to tighten the securty screw...!
2) After then running an Options | Identify Systems this may or may not pull limited information through.
3) as I found out only yesterday, after about 6 weeks of battling on... install the 'WMI Mapper fo HP SIM' (is part of the SIM installation - but I deselected it - oops!) - you can get this seperately from HP.com.
Run the ID Systems again, and you should start getting somewhere...
You (with any luck if you're running on a LAN) should get more info than I can. I keep getting 'No WBEM Support detected' errors - and I'm working like mad to get WBEM working - not sure it will over a WAN with no Domain Trusts though...
Like I said, I've done quite a bit with SIM recently, and I'm starting to get somewhere! So, if you're still having problems, post back on here, and I'll see what else I can think of.
Also, I hope none of this is teaching you to suck eggs - and apologies if it has...!
Good luck!
Thanks, Mark