Is a separate AS Number required for an Internet Xchange point network.
Deen
Is a separate AS Number required for an Internet Xchange point network.
almost all ixen are at layer two. hence they have no ip addresses, let
alone layer three routing.
of course, the ix provider may also choose to provide services on the side,
such as ntp, measurement, ... those are servers and run at layer three+.
hence they are routed. like other routed networks, if they are multi-
homed, they tend to have their own asn.
randy
> Is a separate AS Number required for an Internet Xchange point network.
>
> almost all ixen are at layer two. hence they have no ip addresses
To expand upon that a little, while an exchange point itself is usually a
layer-2 entity (that's a good thing), the ISPs which are exchanging
traffic across it need to assign IP addresses to their router ports which
are connected to it, and it's good to use a single common block of
addresses for that purpose, and manage them in such a way that the in-addr
DNS for the block provides useful information about which ISP they're
associated with, and contact info, and so forth. IP addresses are
available for this purpose from Bill Manning, bmanning@ep.net, who also
provides a management infrastructure for registering the in-addr names and
contact information.
> the ix provider may also choose to provide services on the side...
> Like other routed networks, if they are multi-homed, they tend to
> have their own asn.
One of the services that some exchange points choose to provide is a
route-server or "looking glass" which is a router which all or most of the
others peer with, and which either forwards routes between the other peers
(aggregating the routes into single peering sessions) or allows
participants to log in and see what routes other participants are or
should be offering. As a BGP peer, this obviously needs an AS of its own.
Packet Clearing House, a research organization that I coordinate, offers
free route-servers to exchange points, and we also provide the AS number
for the route-servers.
Lastly, I do hope that you're seriously considering putting up an exchange
point in Sri Lanka and encourage you to do so... Local and regional
exchanges are a great boon to improving the quality of the Internet, and
I'm sure that beyond Randy Bush, Bill Manning, and myself, who're involved
with assisting in new EP construction routinely, that you could expect
support, advice, and assistance from the rest of the networking community
generally. Good luck!
-Bill
BGP Route Reflector IXPs need a AS number. I'll send you a URL with a
whitepaper. The BGP Route Reflector IXPs have proved to offer a low entry
cost for ISPs (for those places that do not have the deep pockets to get big
routers). It also does not remove the option of scaling to point-to-point
peering (pointed out below does not need an AS number) or route server
(which also does not need a AS number).
Hello Deen,
Check out the following URL for a whitepaper and presentation on IXPs:
http://www.cisco.com/public/cons/isp/ixp/
I recommend this model, since it has proven to work.
Q. Is this a commercial IXP project or a project driven by the ISPs
collectively?
Barry
BGP Route Reflector IXPs need a AS number. I'll send you a URL with a
whitepaper. The BGP Route Reflector IXPs have proved to offer a low entry
cost for ISPs (for those places that do not have the deep pockets to get
big routers).
except that big routers are not needed for small-isp exchanges. remember,
an isp participating in such an exchange has only to add the prefixes of
their local peers to their routing, typically a dozen or so. there are very
successful layer-two exchanges where the peers use what we think of as cpe
routers, e.g. cisco 2501s. and what's nice is that this is on the right
path to exchange growth.
l3 exchange ponints are a labor suck and are fragile.
randy
The use of a BGP Route Reflector at an L2 IXP does not make it a L3 IXP.
IMHO - L3 IXPs do not work any more. The "IXs" that use them are really
'international transit services' using the "IX" term to sell their service.
The IXPs with lots of 2501s have scaled because of BGP Route Reflectors. The
RR is a cheap low maintenance, low learning curve alternative to a Router
Server. We know that cause it has proven it self in action for the past four
years. Over time, the IXP can transition from a RR to a RS - like some large
IXPs are doing now.
The use of a BGP Route Reflector at an L2 IXP does not make it a L3 IXP.
IMHO - L3 IXPs do not work any more. The "IXs" that use them are really
'international transit services' using the "IX" term to sell their service.
strongly agreed!
The IXPs with lots of 2501s have scaled because of BGP Route Reflectors.
The RR is a cheap low maintenance, low learning curve alternative to a
Router Server. We know that cause it has proven it self in action for the
past four years. Over time, the IXP can transition from a RR to a RS -
like some large IXPs are doing now.
here i quibble. i don't really like either reflectors or route servers.
let's ignore route servers.
what does an rr do for me other than slightly delay the isps having to
upgrade from a 25xx class router?
at the beginning, there are usually few enough peers and routes that a
simple switch and 25xx will do.
at the point where pure 25xx and switching (no rs no rr) starts to max out,
we're already getting on the steeper part of the growth curve. so the rr
solution will not be long lived, and the financial benefits of the ix are
very clear.
so, rather than do the rr thing, which is labor intensive and a dead end in
the long run, just jump to routers that can handle it, like small 36xx (or
26xx if they have the ram, i really don't know that end of your products
well).
randy
here i quibble. i don't really like either reflectors or route servers.
let's ignore route servers.
so, rather than do the rr thing, which is labor intensive and a dead end in
the long run, just jump to routers that can handle it, like small 36xx (or
26xx if they have the ram, i really don't know that end of your products
well).
Many small providers aren't very good at filtering their routes in
the first place. Sloppiness in a mini-nap is expected.
One person with a little clue and a route server can make _everyones_
lives easier in such a situation.
Scaling routers is relatively easy. Scaling clue is harder.
(Note that I wont disagree that in such a situation, full-mesh
peering is a very viable option.)