nanog mailing list archives

Re: FW: /8s and filtering


From: Harsha Narayan <hnarayan () cs ucsd edu>
Date: Tue, 10 Dec 2002 12:13:49 -0800 (PST)


Hello,
  Thank you very much everyone for all your replies. When Class C space
gets used up, wouldn't the filtering policies have to change to allow the
same kind of multihoming from the Class A space. Currently, a /24 from
Class C is enough to get past filters. However later, a /22 (or is it /20)
from Class A would be required to get past filters.

  Since there are only three /8s left in Class C, I was curious whether
filtering policies would change to accommodate this.

  If filtering policies won't change ARIN will have to change its
multihoming PA policy to giving away a /22 instead of a /24. Though
officially it is RIR policy not to worry about the routability of an
a prefix I guess they do worry about it?

Thanks,
Harsha.


On Tue, 10 Dec 2002 bmanning () vacation karoshi com wrote:



Hello,
  Now I am confused because I have got two sets of contradicting answers.
Some say that anyone can multihome, some say that you need to be of a
certain minimum size to multihome. May I know what is the right answer?

  I agree that allowing anyone to multihome would increase the size of the
routing table. So does this mean that someone has to be of a certain size
to multihome?

Harsha.


      anyone can multihome, with the cooperation of others.
      current practice seems to dictate that the standard
      operating procedures to protect the integrity of
      the routing system mandate that only prefixes of
      certain lengths are allowed at -SOME- isp boundaries.

      you seem to have the assumption that there is a single
      standard here.  There is not.

--bill






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