[c-nsp] BGP v4 multicast

[Phil Mayers]

> 
> Oh, well, if anybody actually starts *using* IPv4 multicast, it might
> return to a more or less working state.
> 
> Our problem was that, since it is hardly ever used, providers tend to
> break it during network changes ("forget to turn on PIM on newly enabled
> circuits", and things like this) - and when people notice that it's broken,
> it's 4 weeks later, and nobody remembers that there was a "recent" change...
> 
> So debugging always was very painful, and had no relation to the amount
> of users...

Funnily enough, that's exactly the problem I'm facing now ("it broken 
sometime since May, fix it")

:o(