[PlanetCCRMA] data over local network

[Yudhi Kusnanto]

> On Mon, May 10, 2010 at 11:36 AM, David Nielson naptastic at comcast.net
wrote:
>>
>> On 05/10/2010 09:00 AM, Oded Ben-Tal wrote:
>> > hi,
>> > thanks for the reply and appologies for being a bit slow. But how do I
>> > assign the ip addresses? We are connecting via a hub (not router) and
the
>> > mac (and my laptop under windows) gets an ip address somehow from the
hub
>> > with the first 2 numbers shared - i.e. mac had 169.256.x.y win had
>> > 169.256.z.q
>> > I think once I get to the successful ping stage we should be fine - we
>> > managed to get OSC messages across with udpsend/receive between max and
>> > pd.
>> >
>> > thanks
>> > Oded
>> >
>> The addresses which start with 169.256 are not real IP
>> addresses--Windows and OS X generate them internally and then flip an
>> internal switch that says "don't even try to connect to the outside
>> world." Getting OSC through under these circumstances is impressive; you
>> shouldn't have been able to.
> 
> I assume the OP meant 169.254, not 256. The 169.254 block is
> link-local, hence 2 machine connected to hub using such addresses will
> communicate just fine. In fact, that's why it worked with the Mac and
> Windows boxes. After failing to get a DHCP lease, both apparently
> fell back to link-local addresses and everything was fine. Many linux
> systems don't follow this behavior, which I think is a property of the
> DHCP client software.
> 

you can also use this feature by installing 'avahi' that provides
'avahi-autoipd' service
 
quote from man page:
 avahi-autoipd implements IPv4LL, "Dynamic Configuration of IPv4 Link-Local
 Addresses" (IETF RFC3927), a protocol for automatic IP address configura‐
 tion from the link-local 169.254.0.0/16 range without the need for a cen‐
 tral server. It is primarily intended to be used in ad-hoc networks which
 lack a DHCP server.

 IPv4LL is part of the Zeroconf stack.

 avahi-autoipd can be used as stand-alone address allocator or as plugin for
 a DHCP client such as ISC's dhclient, where it can be used as fallback
 solution if no DHCP server is found.

 To allow communication between hosts that have only an IPv4LL address
 assigned and hosts that only have a routable IP address assigned you may
 add the following routes to both network configurations:

 route add -net 169.254.0.0 netmask 255.255.0.0 dev eth0 metric 99

 route add default dev eth0 metric 99

 See http://developer.apple.com/qa/qa2004/qa1357.html for more information.

rgds
Yudhi Kusnanto
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