Hello. I want to monitor the cpu and memory usages on my cisco devices using snmp. I found the snmp oids related to cpu in the following page :
But the oids in the table do not work on my devices. For example, I have a cisco 3550 switch with the ip 192.168.1.211, version 12.2(25)when I want to get the informations about the oids up in the table, I got these results:

It shows that the oids cisco given up in the table are not existed in my 3550 switch's MIB. More weird is that when i add a number "1" to
the end of the oid cisco given, I can get some meaningless data for some unkonwn item names like "entreprises.x.x".
For most mib items, the snmp oids work well on my switch. For example, the following graph shows the interface out rate of the swtich:

I think the essence is when I executed the following command:

in all the output results, there's not any item relevant with "cpu" or "memory", but most other items are ok, such as interfaces, as shown below:
IF-MIB::ifDescr.47 = STRING: FastEthernet0/39
IF-MIB::ifDescr.48 = STRING: FastEthernet0/40
IF-MIB::ifDescr.49 = STRING: GigabitEthernet0/1
IF-MIB::ifDescr.50 = STRING: GigabitEthernet0/2
IF-MIB::ifDescr.51 = STRING: Null0
IF-MIB::ifDescr.52 = STRING: Vlan1
IF-MIB::ifType.1 = INTEGER: ethernetCsmacd(6)
IF-MIB::ifType.2 = INTEGER: ethernetCsmacd(6)
IF-MIB::ifType.3 = INTEGER: ethernetCsmacd(6)
IF-MIB::ifType.4 = INTEGER: ethernetCsmacd(6)
IF-MIB::ifType.5 = INTEGER: ethernetCsmacd(6)
So why the cisco given oids won't work on my cisco switch, and how can I get the datas I want? Anyone has some advices? Thanks in advance!
In case the pictures I inserted missing, I attach my problem in the doc.