I see a lot of erroneous blogs for configuring SNMP in ESXi 4.1u1. To set the record straight, here's my erroneous :) blog post for configuring SNMP ESX and ESXi 4.1 and 4.1u1.
VMware Remote CLI is imperative (but not required if you want to use a different method). RCLI should not be confused with PowerCLI. They are different tools and do different things. RCLI contains remote management batch files which use PERL to connect to the VMware API.
Now, Install VMawre Remote CLI. The vCenter server is convenient but your local desktop works too. Once installed, you'll get a command prompt shortcut. If you don't see it, it will be under the start/programs/Vmware/Vmware vSphere CLI. Run it.
Under the directory which RCLI launches, there's a BIN directory. CD BIN to get to that directory. Now the RCLI scripts can execute.
The vicfg-snmp.pl -s displays existing settings. BTW, vicfg-snmp.pl = esxcfg-snmp.pl. They are the same.
vicfg-snmp.pl --username root --password yourpw --server esxihost-s
The vicfg-snmp.pl -D disables SNMP.
vicfg-snmp.pl --username root --password yourpw --server esxihost-D
The vicfg-snmp.pl -t sets the community string and SNMP target server.
vicfg-snmp.pl --username root --password yourpw --server esxihost -t %srvsnmp%/MY-RO -communities MY-RO
The vicfg-snmp.pl -D enables SNMP.
vicfg-snmp.pl --username root --password yourpw --server esxihost
