Configuring additional interfaces

[Jouni Malinen]

On Thu, Sep 19, 2013 at 03:15:08PM +0200, Steffen Dettmer wrote:
> A tutorial suggested:
> 
> iw phy phy0 interface add myAcc type __ap
> ifconfig myAcc hw ether 02:0e:8e:43:33:ff
> ifconfig myAcc 10.27.9.1/24 up
> 
> for each interface. All commands succeed (I found no documentation
> about type "__ap", but it is accepted by iw).

If you do this, you'll be managing the virtual interfaces outside
hostapd and better not configure hostapd to try to add the same
interfaces..

> When starting hostapd, the IP addresses of the interfaces get lost.
> 
> Using debug log shows that hostapd deletes and re-creates the
> interfaces, which explains why IP addresses are lost. Also
> isc-dhcp-server seems to have difficulties and a restart might be
> needed.

This is because of those manual iw interface add commands. If you want
to use them, you would likely be better off not using bss= parameter in
hostapd.conf but instead, run a separate configuration file for each
interface. Anyway, I'd rather two those iw interface add commands.

> Shall I configure interfaces (IP addresses) after starting hostapd?

You will need to do that for each interface that gets added dynamically.

> How do I synchronize not to configure too early?

Netlink events could be used to see when the interfaces get added and
set UP.

> Does hostapd calls some scripts to configure the interfaces or how is
> it inteded to work?

No, there is no such functionality in hostapd currently.

-- 
Jouni Malinen                                            PGP id EFC895FA