Interface mappings table, optional, but strictly advised to have. This file is used by ifrename. iftab file format is described in iftab manpage. Please note that we don't use /etc/iftab, but keep our own /etc/net/iftab. This difference allows to keep /etc/net\-specific filenames with profile and host suffixes under a single directory without creating additional mess in /etc. Additionally it prevents the system from accidental interface name change after ifrename invocation.

Interface mappings table, optional, but strictly advised to have. iftab file format is described in iftab manpage. Please note that /etc/iftab is a separate entity, processed by the ifrename ran by udev. /etc/net/iftab works properly with etcnet profiles and host suffixes, but it's not possible to rename interface using /etc/net/iftab if it the target name is already occupied. Additionally it prevents the system from accidental interface name change after ifrename invocation. Hence, in simple configurations it's easier to use /etc/iftab (e.g. for assigning permanent eth0/eth1/... interfaces), and in complex environments it is advisable to use /etc/net/iftab and custom interface names.