CIDR question

Curtis Villamizar curtis at
Thu Jul 29 16:23:06 UTC 1993

>   On a more substantial note, one issue that was raised at
> the IETF concerned the idea of subnetting with CIDR (as opposed
> to supernetting). When do you think that the NIC(s) will be able
> to hand out pieces of what we now think of as class A nets,
> for example? My thought is that not only will a very large portion
> of the Internet need to be CIDR-ized before this happens, but
> several routers will need to have significant changes to the way
> forwarding works. Does anyone agree with this?
> 	Mark

Here's my two cents.

Its way too early to be considering handing out subnets of class A's.
For class A's that want be announced as peices of class A, that should
be fine as long as they have a single provider who is CIDR/BGP4
capable and can aggregate to a full class A for the rest of the world.

The decision gets a bit more difficult for a class A that wnats to be
subnetted and has multiple providers that are all CIDR/BGP4 capable.
I'd say that this is still possible since the multiple providers can
each aggregate to a full class A and pass the aggregate to the rest of
the world, who in turn can do the primary, secondary, etc thing
pointing at the whole class A.  I don't think there is a case where
you would be worse off than when announcing the whole class A to each
CIDR/BGP4 provider.

This sounds to me like it would cover what the class A networks would
like to do.  Did I miss anything?  I wasn't at Amsterdam or the
regional techs meetings, so I extend my appologies if this is
meaningless or wrong or previously discussed.


BTW - Are the routers needing significant changes ours?  If so, we're
not very far from deploying gated and fixing this.

More information about the NANOG mailing list