PI IP Space and Routing

[Dinkytoy]

Hi,

Anyone here with any experience of PI IP applications?

I'm a little concerned on how routable a small /24 or /23 subnet would be over the internet if it were granted?

Anyone able to offer advice on this?

Thanks.

PS. If there is a better forum to post this on let me know, I did look but think this one is probably the best.

 

[Press2Esc]

PI IP applications?

 

[Dinkytoy]

Provider Independant IP space, application via RIPE.

Situation is now being sorted through our ISP(s).

 

[dtrtel]

I've been out of the ISP biz for a couple of years, but in the US (most regional authorities follow ARIN) backbone providers filter BGP announcements on /21 prefix or shorter. With the near death of competition in ISPs here, the rules may be even tighter now. BGP will announce a /24, but very few if any providers will accept PI longer than /21, because their peers won't accept it. So the best you could do it communicate with "that" ISP, and possibly a handful of others that you can beg, plead, bribe to accept it (ie, place in their routing tables) as well.

If you are trying to multi-home (ie, more than one ISP for redundancy), PI is not the solution. You would announce /24 or shorter (/23 ,/22, etc) from one of your ISP's address blocks and ask the other ISP to accept and propogate your more specific route from the other ISP so you can be reached from either connection.

Sorry, this is a way to do it, but not PI. You have to be able to justify an allocation large enough for "all" providers to accept your BGP advertisements. Not sure what RIPE requires to justify allocation of IP block large enough. Here in the US, it is by RFC 2050 guidelines, and usually, $500 a year for per /21.


--jeff

http://linkedin.com/in/JeffLynch

 

[Dinkytoy]

Thanks for the reply, that's the sort of information I'm after. I'm going to put this over to our ISP(s) and see what they come back with.

I've read through the RFC guidelines and they do mention explicitly what we want to do:


2.1 Guidelines for Internet Service Providers (ISPs)
.......
To facilitate hierarchical addressing, implemented using Classless
Inter-Domain Routing (CIDR), all other ISPs should request address
space directly from its upstream provider. ISPs only request address
space directly from regional registries if their immediate
requirement, when satisfied with a contiguous block allocation, has a
reasonable probability of being routable on the Internet, and they
meet one or more of the following conditions.

a) the ISP is directly connected to a major routing exchange
(for purposes of this document, a major routing exchange
is defined as a neutral layer 2 exchange point connecting
four or more unrelated ISPs.)

b) the ISP is multi-homed, that is, it has more than one
simultaneous connection to the global Internet and no
connection is favored over the other

Note that addresses issued directly from the IRs (non-provider
based), are the least likely to be routable across the Internet.
.......


There are several statements elsewhere within the RFC indicating that no address space obtained this way is guaranteed to be routable. I don't know how much of this is covering their own ass with regard to smaller ranges.

It does indicate to me though reading through the RFC that /24 should be ok, longer though would be a problem.

I'll see what our ISP(s) say on matter, but they did seem to indicate that they have similar customers doing similar things ok. But I do know that if some of our clients, clients in the States suddenly can't reach us there will be hell to pay.

Thanks for your input.

 

[dtrtel]

Be prepared to pay hell if you don't get at least a /21 from your regional authority. This is not just a technical concern from the FUD surrounding the fast increasing "global routing table" (which has been hugely mitigated by CIDR and NAT), but also, if you subscribe to conspiracy theorists, some could posit an intentional raising of the barrier of entry to growing ISP competition.

You'll still need to buy transit from a backbone provider, peering at regional interexchange points will only get you minnimal multi-lateral agreement to accept your BGP peer announcements shorter than /21 (in PI space that is). If you buy transit that solves one problem, the other is getting others to accept you as a peer from a business perspective.

You'll also need to register with the routing arbiter to verify you are accountable for the PI space if you get an allocation.

Best regards,

--jeff

http://linkedin.com/in/JeffLynch

 

[burtsbees]

I can't wait for IPv6 to be in full swing...

Burt

 

[dtrtel]

Me too. It could resemble y2k for Network
professional demand. The issue will probably
have to be forced on corporate America, and
in other countries.

But, sadly, I wouldn't expect to see anything in the
way of improved competition for the business
side of the Internet.


--jeff

http://linkedin.com/in/JeffLynch

 

[burtsbees]

Just wait until they figure out a way to populate the moon---then we'll need IPv6.1
ha ha ha

Burt