[c-nsp] Growing BGP tables

[David J. Hughes]

> For the record there were only two people
> that attached cases to:


That's incredible.  I can't believe that so few people would see the 
benefit in this.  I know one of those attachments was mine.



> What about if we just had a per neighbor filter that
> would filter out more specific prefixes as they come in.
> Once the more specific is filtered then it's gone until
> you do a soft clear to get it back.


I think this breaks the semantics that we all rely upon too much.  
Having a specific prefix disappear from some other bloke's network 
because I remove a supernet isn't really a nice situation to be in.  
Particularly as I can't do the soft reset for him.

However, going out into theoretical realms here, the main problem is 
the RIB / FIB consumption right?  Would there be a chance that the 
removed prefixes could be stored in another are of RAM in a compact 
manner and tagged with the prefix that caused them to be filtered.  If 
the non-filtered prefix is removed then the filtered prefixed could be 
reinstated.  This would allow the current semantics to remain while 
still giving us some of the benefits we are looking for.

Once again, not knowing anything about the internals of IOS's BGP 
implementation etc, would something like that be possible or am I 
barking mad.


David
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