Mailing List Archive: classless nets and home ASs

classless nets and home ASs

Apr 25, 1994, 1:06 PM

Post #1 of 4 (1769 views)

Andrew,

> (& all of the ASs behind them) have withdrawn more specific routes. If
> you could identify the home-ASs of the withdrawn nets, that would
> probably be more helpful & more accurate.
> --asp@uunet.uu.net (Andrew Partan)
>
During this tranisition from the classful world to the classless,
home ASs still have meaning. It does not seem clear that home ASs
will be relevant when we treat all routes as classless entities,
because most assignments can be further subdivided. There will be
no base unit such as class A, B or C on which to hang the home AS
tag. We may want to move from "one net/one home AS" to "prefix and length/
announcing AS" - since an AS downstream or upstream may aggregate
a subset or superset.

I'm not commenting directly on your suggestion on how to express
meaningful information about the specific nets that AS 701 has
withdrawn from its announcment to AS 690, but trying to explore
how we should look at keeping information about classless entities.
These lists (regional-techs and bgpd) seem like the right place to
discuss what information the operators need in a classless routing
world.
--Elise

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Re: classless nets and home ASs [ In reply to ]

sherk at sura

Apr 25, 1994, 10:37 AM

Post #2 of 4 (1726 views)

Permalink

Elise,
My feeling is that there is some level of atomic aggregation,
below which, you will be using igp routes. This goes back to the
original definition of Autonomous System. I would like to see the home
AS represent that transition from igp routing to egp routing. That is,
if you inject a route into the global routing table, then you have
some level of responsibility for that route and this should be documented
somewhere.

Don't think of it as no more A,B,C networks, but rather as
30 different sizes.

Erik

P.S. Would routing within a AS be sub-atomic routing? :-)

> During this tranisition from the classful world to the classless,
> home ASs still have meaning. It does not seem clear that home ASs
> will be relevant when we treat all routes as classless entities,
> because most assignments can be further subdivided. There will be
> no base unit such as class A, B or C on which to hang the home AS
> tag. We may want to move from "one net/one home AS" to "prefix and length/
> announcing AS" - since an AS downstream or upstream may aggregate
> a subset or superset.
>
> I'm not commenting directly on your suggestion on how to express
> meaningful information about the specific nets that AS 701 has
> withdrawn from its announcment to AS 690, but trying to explore
> how we should look at keeping information about classless entities.
> These lists (regional-techs and bgpd) seem like the right place to
> discuss what information the operators need in a classless routing
> world.
> --Elise
>
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Re: classless nets and home ASs [ In reply to ]

asp at uunet

Apr 25, 1994, 11:13 AM

Post #3 of 4 (1742 views)

Permalink

Re: classless nets and home ASs [ In reply to ]

epg at merit

Apr 25, 1994, 6:24 PM

Post #4 of 4 (1737 views)

Permalink

Andrew,

Is your definition of home-as the RIPE definition?

>
> Home-AS still has meansing for a classless net; just as it does for a
> classfull one.
>

How do you designate home-as for 194.16/16 from 194.16.16/24? 194.16/16
was assigned to organizationX and indicated that the home-as was 701.
Then organizationX gave 194.16.16/24 to companyY who has their own AS 702.
Now the assignment registry can be updated to show these changes in home-AS.

> Routing table entries should have some idea of the 'creator' of that
> entry. Home-AS or aggregator or some such seems to be the most
> useful.
> --asp@uunet.uu.net (Andrew Partan)

But when the classless thingy is routed, home-AS and aggregator-AS can
be inconsistent or there can even be multiple creators of aggregation.
So I am not sure that home-AS means the same thing for classless
entities - or perhaps we need another concept which acknowledges
a classless entity may be included in several supersets all of which
have different aggregator-ASs.

If your definition permits multiple home-as tags per classless net,
then you have answered my question. Thanks.
--Elise
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