nanog mailing list archives

Re: Peering + Transit Circuits


From: Faisal Imtiaz <faisal () snappytelecom net>
Date: Tue, 18 Aug 2015 23:27:53 +0000 (GMT)

Thanks for the explanation, 
I am still trying to figure out the realistic business case where doing something like this would make sense to any 
party. 
(unless purely malicious or in error). 

Regards 

Faisal Imtiaz 
Snappy Internet & Telecom 

From: "Pshem Kowalczyk" <pshem.k () gmail com>
To: "Faisal Imtiaz" <faisal () snappytelecom net>, "Tim Durack" <tdurack () gmail com>
Cc: "nanog list" <nanog () nanog org>, cisco-nsp () puck nether net
Sent: Tuesday, August 18, 2015 7:00:35 PM
Subject: Re: Peering + Transit Circuits

It's actually quite easy.
Provider1 is present at Exchange1 and Exchange2, so is Provider2. Provider2
doesn't want to pay for the traffic between Exchange1 and Exchange2, so it
points a static route for all prefixes it has in Exchange2 via Provider1's IP
address in Exchange1 and does the same in Exchange2. Provider1's router
receives traffic, checks where it should go (Exchange2) and it forwards the
traffic. So the traffic flows like this:

Provider2 (Exchange1) -> Provider1 -> (Exchange2) Provider2, all due to static
routes.

kind regards
Pshem

On Wed, 19 Aug 2015 at 10:38 Faisal Imtiaz < faisal () snappytelecom net > wrote:

Let me start backwards...

To me 'peering' is sharing internal routes and downstream customer routes,and
not external ones.
IP transit is all of the external routes including internal routes & downstream
customer routes

Having said that..... if one is control of what IP Prefixes get advertised to
whom... how exactly someone (peers) 'steal' transit ?
(If one is not managing the filters well then yes it is possible, but that would
be a configuration error ?)

Maybe I am naive, to my Peering routes (relationships) are a subset of IP
Transit Routes (relationships)

Based on above belief...

Then Item # 3, becomes the choice of the OP.... where one can make one of two
starting assumptions... We will trust everything coming in and change what we
don't like... or We will not trust anything coming in, and change (accept) what
we like.

Items # 1 & 2, would be a function of network design, technical requirements
(maintenance window) etc etc.. easier to deal with a distributed edge vs all in
one when one has to bring anything down for any reason..

I am open to learning and being corrected if any of the above is wrong !

Faisal Imtiaz
Snappy Internet & Telecom

----- Original Message -----
From: "Tim Durack" < tdurack () gmail com >
To: cisco-nsp () puck nether net , "nanog list" < nanog () nanog org >
Sent: Tuesday, August 18, 2015 8:29:31 AM
Subject: Peering + Transit Circuits

Question: What is the preferred practice for separating peering and transit
circuits?

1. Terminate peering and transit on separate routers.
2. Terminate peering and transit circuits in separate VRFs.
3. QoS/QPPB (
https://www.nanog.org/meetings/nanog42/presentations/DavidSmith-PeeringPolicyEnforcement.pdf
)
4. Don't worry about peers stealing transit.
5. What is peering?

Your comments are appreciated.

--
Tim:>


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