SNMP discovery not working through ISA firewall

[LarsL]

Hi

I have a HPSIM 5.1 with SP1 installation on a subnet trying to discover a server located on another subnet.
there is a ISA firewall inbetween.

The HP-SIM Global protokol settings is configured with
Use the ICMP protokol for system reachabillity (ping) check.
Enable SNMP
Disable WBEM
Disable HTTP
Disable DMI

I have the following rules defined in my firewall
HPsim -> Server
Allow: SSH, SNMP, PING, HTTPS, 2301 TCP, 2381 TCP

Server -> HPsim
Allow: 280 TCP, SNMP, SNMP TRAP, PING (reply 0,0 ICMP send), 2301 TCP, 2381 TCP

According to the document "Managing Servers through firewalls with HPSIM.pdf"
http://h10018.www1.hp.com/wwsolutions/misc/hpsim-helpfiles/ManagingHPServers-withHPSIM.pdf
this is the ports to open.

When I discover the server, it is listed under "All Systems" as System Type=Unmanaged, and when I expand the server there is no Product Description.

According to the above document SNMP is supported to retreive these information.

Could you please advise me what additional steps to take.

Regards Lars