All things related to multicast

[Stig Venaas <>]

ken lindahl wrote:
> hi Toerless et al,
>
> Toerless Eckert wrote:  
[...]
> > After all:     There is really nothing in SAP that you could not do 
> > better by     running SAP on a host system (PC, unix, linux,...).
>
>
> we have nearly 100 routers in nearly as many buildings on campus and
> in remote offices. i hope you're not suggesting that we install and
> operate a host system in each of those locations. imo, we're much
> better off being able to use tools on the routers themselves.

Yes, I think it would be helpful to have some such tools on routers as 
well. Personally I think it would have been cool to run something like 
ssmping between routers... I'm somewhat biased when it comes to ssmping 
though :)

With a tool like that you could when needed run ssmping on one router to 
check that you can receive from a given host or router, or on a host 
check that you can receive from a router. ssmping also shows things like 
tree set-up delay, forwarding path changes etc...

Some form of ssmping protocol should probably be standardised in the 
IETF if other than me are interested in implementing it.

Stig

> >     The router is just receiving these messages and you can display
> >     them with "show" commands. Nothing else. The forwarding of SAP,
> >     as already said by someone else on this thread is completely
> >     unaffected.
>
>
> understand that. the "show" commands are exactly what i've used in
> the past.
>
> >     The problem obviously is that because SAP on texithe router is used
> >     ONLY for such random "show" commands by few users, there is
> >     no real business incentive to follow all the newest developments
> >     into decoding new type of SAP messages, so the command also
> >     becomes less and less useful - and it was only of limited use
> >     in the beginning.
>
>
> if there's still business incentive for promoting multicast, then
> there ought to be business incentive for making it as easy as pos-
> sible to debug, and the question becomes how many users think SAP
> listening makes it easier to debug multicast problems. i do, but
> i don't know how many others feel the same.
>
> thanks,
> ken