The default setup of a net-snmp distribution only allows snmpwalk to work on the device that the snmpd is running on:

[localhost with snmpd]<-[snmpwalk run on localhost]: works
[localhost with snmpd]<-[snmpwalk from another device]: does NOT/NEVER WILL work

[localhost with snmpd and a modified snmp.conf]<-[snmpwalk from another device]: WILL work if you understand the principles of operation.

The program, snmpconf, steps thru the decisions in creating a correct snmpd.conf.

Simple snmpd.conf:
rocommunity <my_community_name>
syslocation <my_location>
syscontact <my_contact_email_address>