RE: How many ISPs are out there?

Mailman List Mirror (Read Only)
1

That wouldn't constitute a complete answer because there are MANY local ISPs
that aggregate under a regional. Also, not all regionals (yes, I've found
some exceptions <Qwest?>) use BGP either. Then there is the old route
pre-fixing problem. Not many ISPs, smaller than /19, are going to be doing
effective ASN's either.

2

I would take issue with the assertion that you need a /19 or larger to "be
doing effective ASNs". My understanding is that as long as you get a
block from former class C or "the swamp", you should be visible
everywhere. We recently requested, and got a /21 from 65/8 from Sprint.
A phone call and some pleading got them to change that to 208.8.16.0/21

AFAIK, that's reachable everywhere from AS19975 If that's *not* correct,
I'd sure like to know...

James Smallacombe PlantageNet, Inc. CEO and Janitor
up@3.am http://3.am

3

Having a prefix that happens to be visible from everywhere is different
than having a prefix that belongs to an ASN. Your mail was unclear as
to whether your /21 was its own seperate ASN or not.

I have to wonder why a phone call and pleading were needed to get
it out of 65/8 - was your /21 being filtered or hidden in some way?

4

> My understanding is that as long as you get a
> block from former class C or "the swamp", you should be visible
> everywhere. We recently requested, and got a /21 from 65/8 from Sprint.
> A phone call and some pleading got them to change that to 208.8.16.0/21

Having a prefix that happens to be visible from everywhere is different
than having a prefix that belongs to an ASN. Your mail was unclear as
to whether your /21 was its own seperate ASN or not.

I didn't word that email well at all. 208.8.16.0/21 belongs to our
AS19975

I have to wonder why a phone call and pleading were needed to get
it out of 65/8 - was your /21 being filtered or hidden in some way?

I pleaded to get it changed from 65/8 to 208/8. I *assumed* that having a
/21 from 65/8 would get us filtered by Verio (at least), but that a /21
from 208/8 should not be filtered anywhere.

James Smallacombe PlantageNet, Inc. CEO and Janitor
up@3.am http://3.am

5

up@3.am wrote:

I pleaded to get it changed from 65/8 to 208/8. I *assumed* that having a
/21 from 65/8 would get us filtered by Verio (at least), but that a /21
from 208/8 should not be filtered anywhere.

Speaking from experience, /21 will get you filtered most places. You'd
need a /20 or /19 at least....

You need to check around the lookingglasses for your actual results:
  http://www.traceroute.org/

6

>
> I pleaded to get it changed from 65/8 to 208/8. I *assumed* that having a
> /21 from 65/8 would get us filtered by Verio (at least), but that a /21
> from 208/8 should not be filtered anywhere.
>
Speaking from experience, /21 will get you filtered most places. You'd
need a /20 or /19 at least....

Like I said, that depends on what part of the address space that is from.
I have not seen that to be the case with 208.8.16.0/21

You need to check around the lookingglasses for your actual results:
  http://www.traceroute.org/

I have...every non-broken route server listed sees our announcement. Are
you aware of any that do not?

James Smallacombe PlantageNet, Inc. CEO and Janitor
up@3.am http://3.am

7

For checking the distribution of your BGP advertisements, you should
telnet to route-views.oregon-ix.net and check the routes to your net
block. (If your block is part of a larger CIDR that Sprint is
advertising, then traffic should get to you eventually.)

For checking inbound routes to your own network, I humbly suggest that you
try Traceloop. That's what it's designed for.

Thanks,
Steve

Dashbit - The Leader In Internet Topology
www.dashbit.com www.traceloop.com