Format of snmpwalk instruction

Question

I'm working with SNMP and was given a command to use. However, I'm trying to break it down into its components so I can understand if I need to change anything. I've found documentation on pretty much everything except for the last part.

The command has this structure:

snmpwalk -v 2c -c communityname address.com .1

From my understanding the meaning of this structure is:

snmpwalk - command

-v 2c - specifies that the version is 2c, options are 1, 2c, 3

-c communityname - specifies the community name, which is like a password to an extent

address.com - the address of the computer in question

.1 - What is this ? I can't seem to find much documentation on it.

Answer 1

man snmpwalk and snmpwalk -h should give you the info you need on the various parameters.

The .1 is the OID and it is an optional parameter to that command, and it pinpoints a point in the hierarchical SNMP MIB on the SNMP agent host. The walk will retrieve all OIDs "below" that point.

Have a read at http://www.net-snmp.org and get a SNMP book to learn about SNMP and MIBs and OIDs; but quoting from SNMP wikipedia article:

SNMP itself does not define which information (which variables) a managed system should offer. Rather, SNMP uses an extensible design, where the available information is defined by management information bases (MIBs). MIBs describe the structure of the management data of a device subsystem; they use a hierarchical namespace containing object identifiers (OID). Each OID identifies a variable that can be read or set via SNMP.

EDIT: Here is image to show the OID tree with ".1" i.e. ISO just below the root.