Community String For Server

We have some Cisco servers that are being administrated by Affant. I recently downloaded a network management tool called SolarWinds and it looks really interesting and amazing because it can do so much for network monitoring. It seems that it needs not only the IP address for out server, but also a Community String. I tried the basic defaults (private, public) but they will not connect. I researched online and found some other defaults for a 3COM network, but none of those worked either.

I was going to try and telnet through to the server but port 23 (default telnet port) is closed. Im sure its for security purposes. I also read online that if I used a packet sniffer, I would be able to sniff out packets which hed the community string in them.

However, I could not find a sniffer which would actually do this. Any suggestions on a good packet sniffer that could do this?

Also, If the telnet port is closed, is there any other way I could telnet into the server on a different port? Or maybe use some other way to access the server?
I really want to use this program but I dont think my corperate office would like us to be monitoring it using this third party software, but us IT people dont really care...

If there is anything you can help out with, it would be most appreciated.