real broadcast mode

[Ondrej Zajicek]

On Tue, Dec 06, 2011 at 01:41:38PM +0200, Tapio Haapala wrote:
> Hello,
>
> Bird supports with ospf type broadcast. Looks that it actually means hat  
> you execpt from "type mcast".

Name 'broadcast' for multicast-based interface is from OSPF RFC. So it
is probably expected by others.

> On several networks multicast is broken. Yes it is broken and we cannot  
> do nothing for that because they are metro ethernet and odsl (operator  
> dsl) networks and they are leased from local operators.
> One solution is make mtmp configuration but if you have 100 router it is  
> nightmare.

In your case you probably could try NBMA, although needs more configuration
than broadcast, it is much simpler (and more similar to broadcast) than
PTMP. Advantage is that for a new router, you just have to configure
it to a few (2-3) 'designated' routers responsible for distributing
signalling information on that network.

PTMP is more for a networks where isn't full visibility (i.e. A can speak
with B, B with C, but A cannot directly speak with C). Not sure which
networks has this property (perhaps some old leased-circuit based networks
or ad-hoc wireless networks).

BTW, how IPv6 is supposed to work on that broken network? There are no
broadcasts in IPv6.

> So I humbly asking new feature. It is real broadcast type. Because of  
> compatibility reasons it is unpossible use type bcast for that and  
> rename multicast for type mcast I suggest that new type is rbcast. It is  
> extension over rfc but it is really usefull one. On real broadcast  
> packets send to 255.255.255.255 so they does not get meshed up with  
> multicast specific rules.

Interesting idea, i will probably implement that.

-- 
Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
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