Re: Select wired connection by router mac address?

[Martijn Lievaart <m rtij nl>]

On 05/19/2013 03:42 PM, Pavel Simerda wrote:
> ----- Original Message -----
> > From: "Alexei Colin" <alexei alexeicolin com>
> > To: networkmanager-list gnome org
> > Sent: Sunday, May 19, 2013 5:32:03 AM
> > Subject: Select wired connection by router mac address?
> >
> > Hello,
> >
> > Is it possible to configure NM to select among automatically connectable
> > wired connections based on router mac address? Use case: automatically
> > connect at home and at work to the correct connection.
> Hello,
>
> Short answer: No.
>
> Long answer: At the time of connection selection, this information is not known to NetworkManager. It would 
> be possible with some magic to gather broadcasted information or even perform active checks based on e.g 
> ARP/NDP. Then you could match to more than just a MAC address. Also it would be theoretically possible to 
> transition from one connection configuration to another and then you could even use information from the DHCP 
> exchange. I don't think anyone is working on this, even though it would be interesting and very practical.

There may be another way, use a dispatcher script in 
/etc/NetworkManager/dispatcher.d. Works if both networks use DHCP. 
Something like:

#!/bin/sh
# Script to dispatch NetworkManager events
#
# Runs ifupdown scripts when NetworkManager fiddles with interfaces.
# See NetworkManager(8) for further documentation of the dispatcher events.

# For debug
exec >/var/log/somename.log
exec 2>&1
set -x

MOUNTPOINTS="/some /mount /points"

if [ -z "$1" ]; then
    echo "$0: called with no interface" 1>&2
    exit 1;
fi

# Run the right scripts
case "$2" in
    up)
    NETMASK="<your-home-network>/<netmask>"
        if [ -n "`/sbin/ip -o addr show $IF to $NETMASK`" ]; then
        for mp in $MOUNTPOINTS; do
        if ! mount | grep -q " on $mp "; then
            mount $mp
        fi
        done
        ip ro add <some-target> via <some-router>
    fi
    ;;
    down)
    ip ro del <some-target> via <some-router>
    for mp in $MOUNTPOINTS; do
        if mount | grep -q " on $mp "; then
        umount -l $mp
        fi
    done
    ;;
    hostname)
    exit 0
    ;;
    hostname|dhcp4-change|dhcp6-change|vpn-up|vpn-down)
        # Do nothing
    ;;
    *)
    echo "$0: called with unknown action \`$2'" 1>&2
    exit 1
    ;;
esac