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Our organization is planning to peer with the local internet exchange, we are planning to obtain an AS number to allow us to do this. However I was unsure if we also need our own IP address space to get connectivity. Would anyone be able to clarify this?

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You do understand that peering does not get you Internet connectivity, right? It only allows you to exchange traffic with the particular networks you peer with. (Most networks will not peer with you unless you meet peering requirements that you will definitely not meet.) –  David Schwartz Dec 29 '11 at 9:16
    
The internet exchange that we are looking at is an open exchange and does not have any requirements apart from having an AS number. How does one get connectivity then? –  RayQuang Dec 29 '11 at 9:20
    
The exchange can't force other networks to peer with you. They may not care who peers with who, but the other companies you might hope to peer with will. Did you get a list of networks that meet there that have open peering? Do you need to exchange significant traffic with those particular networks? If not, you are barking up the wrong tree. (And many of them will have traffic minimums. They can't justify the port for a dribble.) –  David Schwartz Dec 29 '11 at 9:23
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I don't want to appear rude here but this is not something you just do after asking around a few places on the Internet and thinking it sounds cool. If you don't know why and you don't have someone on staff who already knows how then I'd strongly suggest that you don't –  RobM Dec 29 '11 at 9:23
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Ask your LIR/RIR to help you. –  Tom O'Connor Dec 29 '11 at 9:26

3 Answers 3

up vote 20 down vote accepted

I think you are either confused or using the wrong terminology. When you "peer" with someone, that means that you exchange traffic with them, more or less as equals, that is between your customers and their customers. The traffic must either originate or terminate on one of the peering networks or one of their customers. You cannot use a peer to reach any network this is not a customer of theirs.

The concept of "peering" is that both providers are at the same level. It is not a form of Internet access -- where one entity provides another with access. (That's called "transit".) Unless you either are Google or peer with Google, for example, you cannot send traffic that is from or to Google over a peering connection.

Most large networks have onerous peering requirements that you will not meet. You will, at a minimum, need a national network. Otherwise, they will have to do the long haul on coast-to-coast traffic in both directions. That's obviously not fair. If you want to peer with someone, you have to split the work close to 50/50. That means you have to do half the long hauling.

You won't be able to pick up many International routes for the same reason -- why should someone else do all the International hauling? That's not fair, and peering is about symmetric fairness.

Essentially, you'd only be able to peer with those networks that have open peering. And you'd need someone on your staff who understands peering in great detail and can coordinate your operations with other networks. Theoretically, so long as you qualify for a large enough block of IP address space from someone, you can peer using that address space. (Though some providers do include minimum address space as part of their peering requirements.)

Why are you looking into peering? Why are you going to an exchange? If you are looking for cheap Internet access, doing all the work yourself is definitely not the way. You lose out on every economy of scale there is.

The internet exchange that we are looking at is an open exchange and does not have any requirements apart from having an AS number.

If you're imagining that this will get you anything that looks like Internet access, you are seriously mistaken. The exchange cannot force another network to peer with you unless they wish to, which will again mean you have to meet their peering requirements.

To be blunt, this makes no sense at all unless two things are the case:

1) You know for a fact that there are networks there that will peer with you, and

2) you know for a fact that you need (or will need) to exchange significant amounts of traffic with those networks or their customers.

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We are looking at peering because we provide VPS services to several of our clients and we are looking for better conectivity than our current upstream provider provides. –  RayQuang Dec 29 '11 at 9:25
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Cannot upvote this highly enough –  Tom O'Connor Dec 29 '11 at 9:26
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@RayQuang Then peering is not what you want. You want transit. You want an AS and connections to two or three providers. (That may be available at this exchange. In that case, the open peering may be a minor bonus. Beware of things like port and cross-connect fees that eat up the savings of going to the exchange. Two or three lines to your place of business may be a better deal. You also typically get better redundancy that way -- imagine if you lose your link to the exchange!) –  David Schwartz Dec 29 '11 at 9:29
    
@RayQuang What you mean is you're looking into how to set up a multi-homed connection. Not peering –  Tom O'Connor Dec 29 '11 at 9:29

Now that the OP has made it clear what he's actually looking for, I can proceed.

In order to set up a decent stable, resilient, network, you need multiple layers of redundancy on the networking stack.

You contact your LIR and ask for some PI space.. Good luck with that. You'll need a minimum of a /23 or /24, as many providers refuse to advertise a block smaller than that.

You can't expect them to advertise a /27 for you, as it'd make routing tables enormous.

So you need to justify 255-512 IP addresses. Good Luck With That. IPV4 exhaustion is making this nearly impossible.

Then you'll need to contact some transit providers. Not knowing who your clients are, how much traffic you'll be using, or where in the world you're based, I can't help with this decision.

Then you'll need some hardware. You need 2 big fat routers. Cisco or Juniper. As long as they can do BGP and handle a full table (512MB of router ram or better).

Then you'll need a sysadmin who understands BGP. I mean, really understands what a MED is, and why you use it, and what communities are for. You'll be looking at someone well trained, and probably highly expensive.

Then you need to get your sysadmin to make it all work together. Might as well make sure he's got a Company AMEX, because it'll cost money, things need to happen, and yes, it's not cheap.

If you find that 50% of your transit traffic was going to one particular AS, then you might like to ask them to peer with you, for mutual savings on yours and their transit costs. That's why you peer. No other reasons really.

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USUS. European RIPE regulations state the minimum routable network segment is 4096 IP addresses ;) At least this was hat it was last time I checked (some years ago). Can be larger now. A /24 is below significant value. an AS requires at least a /19 assigned. For routers. A Mikrotik for 600 USD (1200, 2gb memory update) can handle this nicely ;) –  TomTom Dec 29 '11 at 9:49
    
It won't matter for him. He'll only be talking BGP with people he pays money to. They won't care how big or small his route is. (He may get slightly sub-optimal routes and slightly impaired redundancy, but with at least a /24, it won't likely be significant.) –  David Schwartz Dec 29 '11 at 10:11
    
Mikrotik might be able to do it, but for "real" production use, my money's with Cisco and Juniper. –  Tom O'Connor Dec 29 '11 at 10:22
    
@DavidSchwartz Last time i went through this process, the minimum we could advertise was a /24. –  Tom O'Connor Dec 29 '11 at 10:22
    
If you know what to avoid, PCs work just fine as routers. And I agree, a /24 is a reasonable minimum or you won't actually get the redundancy and shortcuts you're paying for. (Peers of your providers won't accept your route, so outside of their networks you'll only get the benefit of the larger covering route that goes to the provider you got the address from. And if that providers loses connectivity to any of those networks, they'll have no route to you at all. Also horrible things happen if your providers lose links to each other.) –  David Schwartz Dec 29 '11 at 10:25

In addtion:

However I was unsure if we also need our own IP address space to get connectivity.

What you say is like "I want a number plate for a car, not sure I need a car for it". An A is an autonomous system (that is where AS comes from) of independently routed IP addresses. WIthout addresses there is no AS. So, you get it backward even here.

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In the uk, you can buy a vanity number plate without having a car for it. It's totally pointless, mind you. –  Tom O'Connor Dec 29 '11 at 10:21

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