• Welcome to Hurricane Electric's IPv6 Tunnel Broker Forums.

BGP View with HE address space

Started by mhosts, August 27, 2010, 05:52:48 AM

Previous topic - Next topic

mhosts

I was wondering if it was possible to setup a BGP tunnel with my ASN but advertise a /48 assigned by HE?

We don't have our own IPv6 allocation ATM....

The form online doesn't accept a block if it's assigned by another non-bgp tunnel.

Thanks in advance!

hvdkooij

Sounds rather dangerous as your /48 is allready part of another AS.

hisken

Quote from: mhosts on August 27, 2010, 05:52:48 AM
I was wondering if it was possible to setup a BGP tunnel with my ASN but advertise a /48 assigned by HE?

We don't have our own IPv6 allocation ATM....

The form online doesn't accept a block if it's assigned by another non-bgp tunnel.

Thanks in advance!

Why would you like to do so?
You'd better request a regular tunnel in such a case, you'll be able to request a /48.

BGP tunnels are only useful if you'd like to use your own allocation  ;)
(correct me if I'm wrong)

mhosts

Quote from: hvdkooij on August 27, 2010, 06:24:38 AM
Sounds rather dangerous as your /48 is allready part of another AS.

I don't understand how this is dangerous... please explain.


mhosts

Quote from: hisken on August 27, 2010, 06:32:51 AM
Why would you like to do so?
You'd better request a regular tunnel in such a case, you'll be able to request a /48.

BGP tunnels are only useful if you'd like to use your own allocation  ;)
(correct me if I'm wrong)

You don't have to have your own allocation to use BGP. there are many small ISP's out there who don't have their own assigned RIR IP space and get a "reassignment" from one of their Upstream ISP's.

Example (We're talking IPv4 now beacuse I'm still rather new to the IPv6 and common prefix lengths):

ISP1 has a /16 and reassignes a /24 to ISP2

ISP2 runs BGP and advertisises the /24 back to ISP1 and also has the ability to advertise that /24 to other ISP's/Peers

It's no different with IPv6.

All i'm asking is to be able to use HE address space instead of applying for my own... For now.

hisken

Quote from: mhosts on August 27, 2010, 06:41:44 AM
You don't have to have your own allocation to use BGP. there are many small ISP's out there who don't have their own assigned RIR IP space and get a "reassignment" from one of their Upstream ISP's.
Yeah, I know. But in the case of HE Tunnel Broker the only useful thing about BGP Tunnels is that you could advertise your own allocation to HE, who can route it for you through a tunnel.

Quote
All i'm asking is to be able to use HE address space instead of applying for my own... For now.
You'll get this exactly in the form of a regular tunnel.

Otherwise you would get such an odd situation:
* HE is advertising a /48 out of their /32.
* You are advertising that /48 back to HE.
* HE will route it through a tunnel for you.

(I'm not sure that's possible anyway  :P)

broquea

You need your own IPv6 allocation and ASN. If you already have your own ASN and IPv4 allocations, getting IPv6 is trivial. And depending on the RIR, could also cost $0.

mhosts

Quote from: broquea on August 27, 2010, 07:06:51 AM
You need your own IPv6 allocation and ASN. If you already have your own ASN and IPv4 allocations, getting IPv6 is trivial. And depending on the RIR, could also cost $0.

We have our own ASN but we get our addresses from our upstream ISP as we don't qualify for the minimum /22 from ARIN ATM..

broquea

Shouldn't be hard to qualify for a /48 of PI. Just have to be able to spend the money once a year.

patrickdk

Advertizing a subset of ip space, from another asn, like your requesting, is not that easy.

Most routers, will see the larger allocation of ip space, and ignore your smaller router completely. In order to fix this, the asn that your block came out of, must split up their large block, so the block they gave you is a seperate independent advertisement. So he's block (/32 if it is, not sure) would have to be split up into atleast 3, if not more blocks, an ipblock before your allocation, your allocation, and the rest of it above your allocation. I doubt your allocation will fall nicely, so they will probably end up with 10+ advertisements to do this request. And the more of these they do, the more split up their routes become in bgp.

maestroevolution

patrickdk:

I mean no offense... but that post is incorrect.  Just about everything in it is incorrect.

Internet routing (IPv4/v6) always routes based on longest-prefix.   Always always always***

If ISP A advertised a /16 and ISP B advertises a /24, all traffic to that /24 goes to ISP B.

In an enterprise, advertisement of overlapping routes in different directions is frowned upon, but it happens all the time with ISPs.  Any multihomed customer is going to advertise their address space via two different ISPs.

Regards,

Joel


*** Ok, there is filter-based-forwarding, source-class-forwarding, and old-school PBR, but that's beyond the scope of this post.

patrickdk

Maybe I got it backwards, but still the same issue

You won't have any control over it, the shortest prefix will win.

If your connection to the larger prefix goes down, you will have no way to get that removed, cause it's part of their prefix, unless it get split out.

lukec

patrickdk:
That's exactly what broquea is referring to when he mentions PI space.

mhosts:
The following link should assist you...Request PI (Provider Independant) IPv6 space from your ISP. The "not qualifying for a  /22" argument holds for IPv4 but I would be supprised if it's got anything to do with v6.... Looks like ARIN is your RIR so the below link explains the "rules". Have what your IPS obtains on your behalf associated with your ASN (32 bit?)
ttps://www.arin.net/policy/nrpm.html

With a BGP tunnel to HE they "may" (Idon't know) accept a BGP peering with you, if you have valid PI IPv6 space...(RIPE PI space would be from 2001:678::/29)
OR possibly HE have obtained some PI space that they could allocate to you...(broquea?)

Regards
lukec

lukec

Forgot to mention...PI is best used with multihoming...

broquea

We don't provide PI. BGP tunnels are for networks that cannot get a form of native IPv6 connectivity to announce their IPv6 allocations, not for re-announcing HE space.