First put the Microchip.TXT (the MIB file) under /usr/share/snmp/mibs to easily exchange OID canonical form and name vice versa while making dummy. In this case I’ve modify the MIB to have some additional object i.e. name:
$ snmptranslate -m +Microchip -On Microchip::name
.1.3.6.1.4.1.17095.1.1
so we can then use this correct OID for our dummy.

How?

1. use SetMIBValue() in r1.pl

   $agent->SetMIBValue( '.1.3.6.1.4.1.17095.1.1', ASN_OCTET_STR, "Microchip");
   $agent->SetMIBValue( '.1.3.6.1.4.1.17095.3.13', ASN_INTEGER, 82);

2. Feed r1.snmp for playing as in

   $agent->ParseDataFile( '/usr/local/etc/snmp-emulator/r1.snmp', 0 )

   with the content of

   .1.3.6.1.4.1.17095.1.1 = STRING: Microchip
   .1.3.6.1.4.1.17095.3.13 = INTEGER: 82

In all above two examples we can only GET for Raddle to return an answer for each OID. GETNEXT as in bulk snmpwalk won’t give output because they are not sequenced.

A sample of sequenced data inside a real snmpwalk dump is:

$ snmpwalk -v 1 -c public -On localhost
 
.1.3.6.1.2.1.1.1.0 = STRING: Linux xp-racy 2.6.38-10-generic #46~lucid1-Ubuntu SMP Wed Jul 6 18:40:11 UTC 2011 i686
.1.3.6.1.2.1.1.2.0 = OID: .1.3.6.1.4.1.8072.3.2.10
.1.3.6.1.2.1.1.3.0 = Timeticks: (496371) 1:22:43.71
.1.3.6.1.2.1.1.4.0 = STRING: Root  (configure /etc/snmp/snmpd.local.conf)
.1.3.6.1.2.1.1.5.0 = STRING:
.1.3.6.1.2.1.1.6.0 = STRING: Unknown (configure /etc/snmp/snmpd.local.conf)
.1.3.6.1.2.1.1.8.0 = Timeticks: (0) 0:00:00.00
.1.3.6.1.2.1.1.9.1.2.1 = OID: .1.3.6.1.6.3.10.3.1.1
.1.3.6.1.2.1.1.9.1.2.2 = OID: .1.3.6.1.6.3.11.3.1.1

thus, we can only

$ snmpget -m +Microchip -v 1 -c public localhost Microchip::control.13
Microchip::control.13 = INTEGER: 82

or from other system with no Microchip MIB use

$ snmpget -v 1 -c public 192.168.40.105 .1.3.6.1.4.1.17095.3.13
SNMPv2-SMI::enterprises.17095.3.13 = INTEGER: 82

The tree below may visually explains sequenced data for GETNEXT where our Microchip is branched at private.enterprises.microchip :

$ snmptranslate -m +Microchip -Tp
 
+--iso(1)
   |
   +--org(3)
      |
      +--dod(6)
         |
         +--internet(1)
            |
            +--directory(1)
            |
            +--mgmt(2)
            |  |
            |  +--mib-2(1)
            |     |
            |     +--system(1)
            |     |  |
...
            +--private(4)
            |  |
...
            |  +--enterprises(1)
            |     |
...
            |     +--microchip(17095)
            |        |
            |        +--product(1)
            |        |  |

How GET and GETNEXT appeared in SNMP can be viewed by running snmpd in debug mode with this options:

$ snmpd -m +Microchip -f -L -V -C -I vacm_vars -c /usr/local/etc/snmp-emulator/r1.conf
NET-SNMP version 5.3.1
Connection from UDP: [127.0.0.1]:32770
Received SNMP packet(s) from UDP: [127.0.0.1]:32770
  GET message
    -- control.13

net-SNMP packages are required for Raddle to work on top of primarily snmpd.

yum install net-snmp net-snmp-utils

Prior to installation some rpm packages must be downloaded separately as my local repo (created from original RHEL CD images) may not contain them. They are installed as follow:

rpm -i perl-Carp-Clan-6.00-1.el4.rf.noarch.rpm
rpm -i perl-Bit-Vector-6.4-2.el5.rf.i386.rpm
rpm -i perl-Crypt-DES-2.05-3.2.el5.rf.i386.rpm
rpm -i perl-Digest-SHA1-2.11-1.el5.rf.i386.rpm
rpm -i perl-Digest-HMAC-1.01-2.2.el5.rf.noarch.rpm
rpm -i perl-Socket6-0.20-1.el5.rf.i386.rpm
rpm -i perl-Net-SNMP-5.2.0-1.2.el5.rf.noarch.rpm
rpm -i perl-Date-Pcalc-1.2-1.2.el5.rf.noarch.rpm
rpm -i perl-Date-Calc-5.4-1.el5.rf.i386.rpm

continued by installing net-snmp-perl from original repo

yum install net-snmp-perl

Uncompressing Raddle and successful make test will mean installation is good and can be finished by make install

cd Net-Raddle-0.08
perl Makefile.PL
make test
make install

Replaying SNMP Packets

The idea is to run snmpd which replays a specific prepared-SNMP-packets instead of our own real time system SNMP data (in this case the condition of RHEL 5.2 host). There are three files to do that, let’s name them r1.*:

1. r1.snmp
   A capture from i.e.
   snmpwalk -v 1 -c <community string> -OneU <device> > r1.snmp
2. r1.conf
snmpd will run this instead of the original OS default:
   snmpd -C -I vacm_vars -c /usr/local/etc/snmp-emulator/r1.conf
3. r1.pl
   the perl script where the most basic is to just replay the above r1.snmp

An official documentation to replay SNMP can be found here. I got hold back when trying to listen from other host, it turns out that I must remove the localhost section in r1.conf which will make it to use standard port 161 as well

# Listen on port 9501
#agentaddress    udp:localhost:9501,tcp:localhost:9501

It is also wise to always cut the r1.snmp first to see if the perl works (test with perl -w /usr/local/etc/snmp-emulator/r1.pl) either with warning or clean, meaning no problem with just some of the OIDs found inside the file.