SNMP Troubleshooting

Troubleshooting: Ensure that you can successfully SNMP poll for interface names and descriptions:

OID	Symbolic Name	Description	Example Value	Purpose
1.3.6.1.2.1.31.1.1.1.1	ifName	Logical name of the interface (often OS-specific)	eth0, Gi0/1, ge-0/0/0	Used for identifying interfaces by name
1.3.6.1.2.1.2.2.1.2	ifDescr	Human-readable description (often from the OS or vendor)	Intel 82574L Gigabit, FastEthernet0/1	Legacy and commonly supported identifier
1.3.6.1.2.1.31.1.1.1.18	ifAlias	Admin-defined alias or description string	Uplink to Core Switch, DMZ	Allows admins to label interfaces with custom notes
1.3.6.1.2.1.2.2.1.3	ifType	Integer value representing the interface type	6 = Ethernet, 24 = Loopback	Used for filtering by physical/logical interface type

# SNMPv2c Walk Example (using community string)
snmpwalk -v2c \
  -c <COMMUNITY> \                      # SNMP community string (e.g., 'public')
  <HOST> \                              # Target device IP or hostname
  1.3.6.1.2.1.31.1.1.1.1 \              # ifName - Interface name
  1.3.6.1.2.1.31.1.1.1.18 \             # ifAlias - Admin-defined alias
  1.3.6.1.2.1.2.2.1.2 \                 # ifDescr - Interface description
  1.3.6.1.2.1.2.2.1.3                   # ifType - Interface type (numeric code)

# SNMPv3 Walk Example (authPriv security level using SHA-1 and AES-128)
snmpwalk -v3 \
  -l authPriv \                         # Security level: authentication and privacy
  -u <USER> \                           # SNMPv3 username
  -a SHA \                              # Authentication protocol (SHA-1)
  -A <AUTH_PASS> \                      # Authentication password
  -x AES \                              # Privacy protocol (AES-128)
  -X <PRIV_PASS> \                      # Privacy password
  <HOST> \                              # Target device IP or hostname
  1.3.6.1.2.1.31.1.1.1.1 \              # ifName - Interface name
  1.3.6.1.2.1.2.2.1.2 \                 # ifDescr - Interface description
  1.3.6.1.2.1.31.1.1.1.18 \             # ifAlias - Admin-defined alias
  1.3.6.1.2.1.2.2.1.3                   # ifType - Interface type (numeric code)