Discovering Network Devices with SNMP not working

Question

I have implemented SCOM 2012 SP1 CU5 on Server 2008 R2 with SQL 2008 R2 all installed on the same VM running side by side with SCOM 2007 R2 v 6.1.7221.0. I have almost fully decommissioned SCOM 2007 and all that remains on it is 2 network devices that
I cannot discover with SCOM 2012 using SNMP, no matter what I try. If I just use ICMP the discovery works. I have checked both the devices and SNMP is enabled and if I run this snmpwalk command on both devices I get a response;
c:\Support\SNMP Walk>SnmpWalk.exe -r:10.X.X.XX -v:1 -c:"public" -os:.1.3.6.1.
2.1.1 -op:.1.3.6.1.2.1.2
SnmpWalk v1.01 - Copyright (C) 2009 SnmpSoft Company
[ More useful network tools on http://www.snmpsoft.com ]
OID=.1.3.6.1.2.1.1.1.0, Type=OctetString, Value=NetMan 100 plus
OID=.1.3.6.1.2.1.1.2.0, Type=OID, Value=1.3.6.1.4.1.5491.6
OID=.1.3.6.1.2.1.1.3.0, Type=TimeTicks, Value=5 days, 1:58:58.04
OID=.1.3.6.1.2.1.1.4.0, Type=OctetString, Value=SystemsEngineer
OID=.1.3.6.1.2.1.1.5.0, Type=OctetString, Value=MARMUPS
OID=.1.3.6.1.2.1.1.6.0, Type=OctetString, Value=FXXXXX
OID=.1.3.6.1.2.1.1.7.0, Type=Integer, Value=0
Total: 7
c:\Support\SNMP Walk>SnmpWalk.exe -r:10.X.X.1 -v:1 -c:"scom05" -os:.1.3.6.1.2.1
.1 -op:.1.3.6.1.2.1.2
SnmpWalk v1.01 - Copyright (C) 2009 SnmpSoft Company
[ More useful network tools on http://www.snmpsoft.com ]
OID=.1.3.6.1.2.1.1.1.0, Type=OctetString, Value=SSG-140 version 6.3.0r2.0 (SN: 0
185112006000325, Firewall+VPN)
OID=.1.3.6.1.2.1.1.2.0, Type=OID, Value=1.3.6.1.4.1.3224.1.52
OID=.1.3.6.1.2.1.1.3.0, Type=TimeTicks, Value=359 days, 2:20:16.00
OID=.1.3.6.1.2.1.1.4.0, Type=OctetString, Value=Network
OID=.1.3.6.1.2.1.1.5.0, Type=OctetString, Value=XXXXXX
OID=.1.3.6.1.2.1.1.6.0, Type=OctetString, Value=FXXXXX
OID=.1.3.6.1.2.1.1.7.0, Type=Integer, Value=72
Total: 7
The first device is a Marms UPS which has had its firmware upgraded, which was discovered using SNMP in SCOM 2007 and the second device is a Juniper SSG-140 Firewall, again this is discovered using SNMP in SCOM 2007.
I believe that I have setup SNMP correctly on SCOM 2012 because I have 28 other networks devices discovered using SNMP using an explicit discovery, some of these being newer Marms UPS's, emerson air conditioners, netapp SAN etc.
I have added any and all accepted community names in the SNMP service properties on SCOM 2012 and enabled accept SNMP packets from any host.
Does anyone have any information that they could forward to me or point in the right direction to troubleshoot this issue for eg run some snmp get commands and capture / filter traffic with wireshark, what do I look for? Any other logs to check besides the
obvious ones? Any known issues with SCOM 2012 SP1 and SNMP, should I upgrade to R2? It just seems that some network devices get discovered with ease and others do not and I am running out of ideas. Thank you all in advance.

Answer 1

Patrick, thank you for your reply.
Yes the snmpwalk command is run from the new SCOM 2012 server which has the discovery rule on it.
I don't have any pending network devices, its blank.
Could there be an issue with my discovery rule? I have noticed that each time I make a change to, for eg, the access mode and change this from ICMP to ICMP/SNMP, save it, run it, it doesn't seem to update the said network devices access mode's in network
devices, it just stays on ICMP. Do I have to manually remove the network devices which have been discovered before making any changes to the discovery rule and running it which I have done? They don't seem to appear in network devices pending management either?