curl/docs/cmdline-opts/interface.d

c: Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Long: interface
Arg: <name>
Help: Use network INTERFACE (or address)
See-also: dns-interface
Category: connection
Example: --interface eth0 $URL
Added: 7.3
---
Perform an operation using a specified interface. You can enter interface
name, IP address or host name. An example could look like:

 curl --interface eth0:1 https://www.example.com/

If this option is used several times, the last one will be used.

On Linux it can be used to specify a VRF, but the binary needs to either
have CAP_NET_RAW or to be run as root. More information about Linux VRF:
https://www.kernel.org/doc/Documentation/networking/vrf.txt