More Questions of Exchange Points

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1

> are not but that is a nit argument. There are lots of ways to
> slice the exchange point.

I did observe 2 exchange points have direct connection between them, does it mean
they belong to the same switch fabiric?

  What does this mean?

> If -ANY- isp provides transit off the exchange fabric,
> does that make it a transit exchange? If not, why not?

Are those private peering points?

  confusion of terms. When bits cross an administrative boundary
  that can be called a "peering point". Often times that administrative
  boundary has a policy associated with it. Policies may be implementated
  via BGP, ACLS, etc. The pathological case is the T1 between
  Sprint and my home network. The two endpoints of that circuit
  comprise a peering point. Sprint controls one end, I control the
  other and we have agreed to fate share a common communications
  path to swap bits.

  Multiple parties can agree to share a layer 2 media for exchanging
  bits. For Internet, I make the distinction that the layer 1 media
  (glass, copper, freq.) must implement a shared broadcast domain, e.g.
  I can ARP between the MAC addresses of the connecting devices.
  Again, for Internet, the presumption is IP. It is conceivable
  that an operator might get a big'ol switch (layer one) and configure
  it so that ports 1-10 are one broadcast domain, 11 & 12 are a second
  broadcast domain, and 13-20 are a third, leaving 21-24 for the fourt
  broadcast domain. Or... four VLANS. One switch, four networks.
  Assign an IP subnet for each. That would be four exchanges.
  Now Zocalo & JAM, running on the first VLAN/exchange are assigned
  192.168.10.4 and 192.168.10.5 & can ping/peer with everyone else
  on VLAN 1-10. HOWEVER, Zocalo & JAM want to do some nifty/cool
  things that they really don't want anyone else to sniff out.
  So they create a VPN (extra credit for defining at least four
  ways to do this... over the SAME VLAN) and use 10.168.10.4 and
  10.168.10.5 for their private VPN.

  So. Is this one exchange point (one switch), four exchange points
  ( 4 VLANS), or five exchange points ( 5 subnets)? Which ones are
  public? Which ones are private? and why?

2

Troublemaker! :slight_smile:

                                -Bill

3

> I did observe 2 exchange points have direct connection between them, does it mean
> they belong to the same switch fabiric?
  What does this mean?

I mean in a trace (from traceroute probing), 2 exchange points (in Mr
Woodcock's list) are next to each other.

.... ip of AS1, ip of EP1, ip of EP2, ip of AS2, ....

I thought they are connected to each other directly (probably the
connecion is not as simple as the p2p link between 2 routers).

> Are those private peering points?

  confusion of terms. When bits cross an administrative boundary
      [...]

Sorry, I did confuse peering with transit. But I thought those private peering
points are somewhat similiar too the IXs, ISPs exchange traffic there and they
may also provide transit to the customers there.

  So. Is this one exchange point (one switch), four exchange points
  ( 4 VLANS), or five exchange points ( 5 subnets)? Which ones are
  public? Which ones are private? and why?

Is this case very common?

4

> > I did observe 2 exchange points have direct connection between them, does it mean
> > they belong to the same switch fabiric?
I mean in a trace (from traceroute probing), 2 exchange points (in Mr
Woodcock's list) are next to each other.

.... ip of AS1, ip of EP1, ip of EP2, ip of AS2, ....

I thought they are connected to each other directly (probably the
connecion is not as simple as the p2p link between 2 routers).

If they connected directly then you would see only two IPs when tracing
through, one on the ISP side of the router connecting the the IX and one
on the IX side of the next hop router.

Theres prolly some other magic going on to give that trace.

> > Are those private peering points?
>
> confusion of terms. When bits cross an administrative boundary

Sorry, I did confuse peering with transit. But I thought those private peering
points are somewhat similiar too the IXs, ISPs exchange traffic there and they
may also provide transit to the customers there.

The rule is there are no rules, stop drawing boxes

> So. Is this one exchange point (one switch), four exchange points
> ( 4 VLANS), or five exchange points ( 5 subnets)? Which ones are
> public? Which ones are private? and why?

Is this case very common?

Why care, you are now at the level of asking individual ISPs how they
configure their network, and theres a lot of ISPs to ask before you can
begin to answer your question!

As per the previous emails, the only thing that matters here is what you
do on your network which therefore defines what you connect with, how you
connect up and how you configure.

I think your mistaken to believing the Internet is structured and
organised in some way! :slight_smile:

Prof Einstein can offer you some wise words to help right now- that it is
all relative.

Steve

5

Stephen J. Wilcox wrote (to Ruomei Gao):

I think your mistaken to believing the Internet is structured and
organised in some way! :slight_smile:

The internet was an experiment to design a network resiliant to attack,
seeing as www.gov.ps has gone offline when Palestine was attacked, the
experiment is a dismal failure, so we should all pack up and get new
jobs?

:slight_smile:

The internet has a structure from a given viewpoint, a path layed out
before you to any given destination, or at least the rechable ones.
And a different structure from any other viewpoint. You are in a
maze of twisty passages, all alike. Although slightly more asymmetric
than that one.

David.

The Internet is closed for cleaning. Return to your lives, citizens.