.\"
.\" Copyright 2010 by Ben Greear <greearb@candelatech.com>
.\" SPDX-License-Identifier: MIT
.\"
.TH ARES_SET_LOCAL_DEV 3 "23 September 2024"
.SH NAME
ares_set_local_dev \- Bind to a specific network device when creating sockets.
.SH SYNOPSIS
.nf
#include <ares.h>

void ares_set_local_dev(ares_channel_t *\fIchannel\fP, const char* \fIlocal_dev_name\fP)
.fi
.SH DESCRIPTION
The \fBares_set_local_dev\fP function causes all future sockets
to be bound to this device with SO_BINDTODEVICE.  This forces communications
to go over a certain interface, which can be useful on multi-homed machines.
This option is only supported on Linux, the interface must not be already bound to the 
socket or the current effective user must have CAP_NET_RAW capability in the current
network namespace for the option to work.  If SO_BINDTODEVICE is not supported or the
setsockopt call fails (probably because of permissions), the error is
silently ignored.
.SH SEE ALSO
.BR ares_set_local_ip4 (3)
.BR ares_set_local_ip6 (3)
.BR network_namespaces (7)
.SH NOTES
This function was added in c-ares 1.7.4