Python 3.3+socketfunction

socket.if_nametoindex()

network interfaces

Returns the numeric index of a network interface by its name, for example 'lo' gives 1.

Syntax

socket.if_nametoindex(if_name) -> int

Indexes are assigned by the OS and change after a reboot or when an adapter is plugged in, so store the name and look up the index with this function at start-up. An unknown name raises OSError rather than returning 0. On Windows the name must be in the 'ethernet_32770' form that if_nameindex() reports.

Examples

import socket
index, name = socket.if_nameindex()[0]
print(socket.if_nametoindex(name) == index)  # → True
socket.if_nametoindex('nosuch0')  # → OSError: no interface with this name

See also

Common errors

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