ifAlias
Module: IF-MIB
OID (symbolic): IF-MIB::ifAlias
OID (numeric): 1.3.6.1.2.1.31.1.1.1.18
Node type: OBJECT-TYPE
Type: DisplayString
Access: read-write
Description: This object is an 'alias' name for the interface as specified by a network manager, and provides a non-volatile 'handle' for the interface.
On the first instantiation of an interface, the value of ifAlias associated with that interface is the zero-length string. As and when a value is written into an instance of ifAlias through a network management set operation, then the agent must retain the supplied value in the ifAlias instance associated with the same interface for as long as that interface remains instantiated, including across all re- initializations/reboots of the network management system, including those which result in a change of the interface's ifIndex value.
An example of the value which a network manager might store in this object for a WAN interface is the (Telco's) circuit number/identifier of the interface.
Some agents may support write-access only for interfaces having particular values of ifType. An agent which supports write access to this object is required to keep the value in non-volatile storage, but it may limit the length of new values depending on how much storage is already occupied by the current values for other interfaces.
What is ifAlias?
This read-write string, up to 64 characters, lets a network manager assign a persistent 'alias' or handle to an interface, distinct from its ifIndex, that survives reboots and even ifIndex renumbering. Admins use it to attach meaningful, human-readable labels to interfaces, such as circuit numbers or purposes, so monitoring dashboards and reports are easier to read than raw index numbers. For example, an admin sets ifAlias to 'WAN-Circuit-4471-ISP-X' on a router's WAN port so NOC staff instantly recognize which link is affected in an alert.
Examples
Walk all instances (SNMPv2c):
snmpwalk -v2c -c public <target> 1.3.6.1.2.1.31.1.1.1.18 snmpwalk -v2c -c public <target> IF-MIB::ifAlias
Get a specific instance (index 1):
snmpget -v2c -c public <target> 1.3.6.1.2.1.31.1.1.1.18.1 snmpget -v2c -c public <target> IF-MIB::ifAlias.1
Set instance 1 (SNMPv2c):
snmpset -v2c -c private <target> 1.3.6.1.2.1.31.1.1.1.18.1 s <value>
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OID Breakdown
Upper-level ancestors (6 from the standard OID tree / other modules)
| Numeric OID | Name | Module |
|---|---|---|
| 1 | iso | LANART-AGENT |
| 1.3 | org | AirPair-MIB |
| 1.3.6 | dod | AirPair-MIB |
| 1.3.6.1 | internet | AirPair-MIB |
| 1.3.6.1.2 | mgmt | AXON-MIB |
| 1.3.6.1.2.1 | mib_2 | AXON-MIB |
| Numeric OID | Name | Module |
|---|---|---|
| 1.3.6.1.2.1.31 | ifMIB | IF-MIB |
| 1.3.6.1.2.1.31.1 | ifMIBObjects | IF-MIB |
| 1.3.6.1.2.1.31.1.1 | ifXTable | IF-MIB |
| 1.3.6.1.2.1.31.1.1.1 | ifXEntry | IF-MIB |
| 1.3.6.1.2.1.31.1.1.1.18 | ifAlias | IF-MIB |