Jalasoft which offers the ability to extend OpsMgr capabilities in monitoring of network devices through it's Xian IO Network Manager has come out with a FREE SNMP simulation tool called Jalasoft SNMP Device Simulator v2.6. It has a user friendly user interface and allows you to simulate
- Cisco Switches
- Cisco Router
- Cisco Firewalls
- Cisco VPN Concentrators
- Cisco Wireless devices
- 3Com Switches
- HP Procurve Switches
- F5 BigIp
- Nortel
- APC UPS

For more information and where to download this free tool, go to this link:
http://www.jalasoft.com/Web/Product/Product.aspx?id=49