Snmp Mib Basics
SNMP is nice but MIB translations can be a pain. It can also be necessary for figuring out what certain numbers mean in the MIB tree.
Where does SNMP look for MIBs?
net-snmp-config –default-mibdirs
Make user specific directory (needs to be in above path)
mkdir -p /home/
/.snmp/mibs
Grab MIB data from Cisco (or wherever)
Example MIB for Firewall info: ftp://ftp.cisco.com/pub/mibs/v2/CISCO-UNIFIED-FIREWALL-MIB.my
copy to..
/home/<me>/.snmp/mibs/CISCO-UNIFIED-FIREWALL-MIB
Enable MIB
Find out where SNMP is looking for configuration parameters:
net-snmp-config –snmpconfpath
Edit your user snmp configuration (if path is included in above command)
n /home/
/.snmp/snmp.conf mib +CISCO-UNIFIED-FIREWALL-MIB
Try walking the top OID tree
snmpwalk -v2c
MIB search path: /home/<me>/.snmp/mibs:/usr/share/mibs/site:/usr/share/snmp/mibs:/usr/share/mibs/iana:/usr/share/mibs/ietf:/usr/share/mibs/netsnmp
Cannot find module (CISCO-SMI): At line 37 in /home/<me>/.snmp/mibs/CISCO-UNIFIED-FIREWALL-MIB
Cannot find module (CISCO-FIREWALL-TC): At line 46 in /home/<me>/.snmp/mibs/CISCO-UNIFIED-FIREWALL-MIB
What’s with? ‘Cannot find module’
This means there are MIB dependencies. You can probably retrieve these from ftp://ftp.cisco.com/pub/mibs/v2.
/home/<me>/.snmp/mibs/CISCO-SMI
/home/<me>/.snmp/mibs/CISCO-FIREWALL-TC
Enable these MIBs as well.
Walk the tree and enjoy MIB goodness
@ :~# snmpwalk -v2c -c >> snmpinfo.txt
Show me the basic SNMP catagories
cut -d: -f 1 snmpinfo.txt uniq sort
SNMPv2-MIB
Technical Support
Copyright (c) 1986-2013 by Cisco Systems, Inc.
SNMPv2-MIB
DISMAN-EVENT-MIB
SNMPv2-MIB
IF-MIB
RFC1213-MIB
IP-MIB
IP-FORWARD-MIB
IP-MIB
TCP-MIB
UDP-MIB
SNMPv2-SMI
SNMPv2-MIB
SNMPv2-SMI
You can check out DISMAN-EVENT-MIB using grep. If you find a MIB you can use SNMPGET next time.
Retrieve Uptime Using MIB’s and SNMPGET
@ :~# snmpget -v2c -c DISMAN-EVENT-MIB::sysUpTimeInstance
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (151866995) 17 days, 13:51:09.95