[MLB-WIRELESS] Launching The Automagic Firmware Builder

[Dan Flett]

The /16 netmask is a feature, not a fault.  The Freifunk Firmware is
generally used on a single-radio node in adhoc mode with an omni antenna.  A
/16 netmask allows such a node to talk to other such nodes without needing
to co-ordinate IP addresses.  If you use a /28, you will need to tell your
immediate neighbours to have IP addresses in your address range.

The intention of the design of the Freifunk Firmware and the Automagic
Firmware Builder is that people use the IP address range and netmask
allocated to them.  A /16 netmask on your wireless interface will not upset
the rest of the network - broadcast traffic is not (yet) relayed by OLSR,
and OLSR nodes only advertise themselves as a /32 route.

It is true that the address range allocated to you is a /28 - if you want to
advertise your entire /28 to the rest of the network you can add it as an
entry in the "HNA4" box.  But you only need to do this if you have non-OLSR
nodes with static IP addresses in your allocation.  Nodes with DHCP-assigned
addresses (from the Freifunk node) can still talk to the rest of the network
via NAT.

If you are using more than one radio on your node and/or your Freifunk node
is doing a point-to-point link, then by all means, use a /28 on the
point-to-point radio(s) - interfaces with narrower netmasks get higher
priority in routing tables (if two different routes to the same IP address
exist) and so give your point-to-point links priority compared to your omni
interface.

Cheers,

Dan

> -----Original Message-----
> From: melbwireless-bounces at wireless.org.au 
> [mailto:melbwireless-bounces at wireless.org.au] On Behalf Of 
> Chris Samuel
> Sent: Monday, 4 December 2006 11:31 PM
> To: melbwireless at wireless.org.au
> Subject: Re: [MLB-WIRELESS] Launching The Automagic Firmware Builder
> 
> On Monday 04 December 2006 9:28 pm, Chris Samuel wrote:
> 
> > One thing i noticed that puzzled me, in the WLAN config page it 
> > initially said that my addres range was 10.10.128.128 with a /16 
> > netmask, rather than a /28.
> >
> > I might reflash it to see whether it drops back to that again or 
> > whether it was a (wrong) setting I had before..
> 
> Reflashing does indeed set the WLAN netmask to a /16 and I 
> had to reset it via the web interface to a /28.
> 
> cheers,
> Chris
> --
>  Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC
> 
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