[Linux-cluster] TTL on multicast packets set to 1 by default?

[Nikolas Lam]

On Wed, 2007-09-19 at 11:26 +0100, Steven Whitehouse wrote:
> Hi,
> 
> On Wed, 2007-09-19 at 01:25 -0700, Steven Dake wrote:
> > My apologies I must have missed that email.
> > 
> > The code in openais is untested in a routed environment because I dont
> > have any routed environments to test with.  This is why TTL is not
> > configurable in the current openais or tested with any values greater
> > then 1.  I can build you an RPM with ttl set to some greater value to
> > test with if you like.
> > 
> > Regards
> > -steve
> 
> The normal settings for multicast ttl are:
> 0 - node local
> 1 - link local
> <32 - site local (so I guess a setting of 31 is reasonable here)
> >128 - global
> 
> I also found a ref with the following extra values which I didn't
> remember:
> 33-64 region local
> 65-128 continent local
> 
> I'm not sure if those last couple are official or not, 
> 
> Steve.

Thanks Steve(s),

We're a pretty big site (a university), so it's possible (but unlikely)
that a legitimate round-about route could consume up to around approx 30
hops. We're using a multicast range which is not being routed outside
the university, so it's probably fine to set it to 128.


Nik