[AusNOG] BGP query

[Mark ZZZ Smith]

>________________________________
> From: Nathan Brookfield <Nathan.Brookfield at simtronic.com.au>
>To: Alex Samad - Yieldbroker <Alex.Samad at yieldbroker.com> 
>Cc: "ausnog at lists.ausnog.net" <ausnog at lists.ausnog.net> 
>Sent: Tuesday, 10 June 2014 10:41 AM
>Subject: Re: [AusNOG] BGP query
> 
>
>
>TPG want to influence traffic to traverse via Transit links which are more expensive than via Peering exchanges (even there own).
>
>
>It's a silly network strategy and only hurts there own customers but at the same time increases the amount of bandwidth required by PIPE Transit customers which equals more revenue :(
>

Actually, it hurts all their competitors attached to the IX, because it is cheap for TPG to send out their own transit (because there is usually unused yet paid for outbound capacity), where as for their competitors, it is inbound on transit links for which only the needed inbound capacity is purchased. IOW, their competitors have to buy more (inbound) transit capacity for traffic that should be instead coming over their peering links.


I think the only time this would be acceptable would be during a lead time while a peering link capacity upgrade is being organised. Even then, that is a predictable event and therefore should normally be ready when it is needed. A measure like this should be very temporary if it is necessary at all.


If this has been ongoing, TPG want to benefit from peering inbound to their network, but don't want their IX peers to gain the same benefit.

You can't selectively AS prepend towards only them, however you can send more specific routes into the IX to make them preferred over your transit announced aggregates. Your 'good' peers shouldn't care too much because they'll be preferring peering routes anyway (all it costs them is some additional route table slots), and your 'bad' peer will have to work harder to avoid providing the mutual benefit multilateral peering is supposed to provide to everybody. They could of course easily drop all of your routes they receive over the IX ... and you could do the same to theirs if they're willing to go that far.

It's in everybody's interests to accept and prefer all routes received over peering.




>
>PS I love path stuffing but the term technically is path prepending.
>
>
>Kindest Regards,
Nathan Brookfield 
>
>
>Chief Executive Officer
>Simtronic Technologies Pty Ltd
>
>
>Web: http://simtronic.com.au
>Phone: 1300 592 330
>Fax: (02) 4749 4950
>
>
>
>
>On 10 Jun 2014, at 10:31, "Alex Samad - Yieldbroker" <Alex.Samad at yieldbroker.com> wrote:
>
>
>Hi
>
>I noticed something strange on the weekend with my BGP setup. Thought I would ask the group if it looks strange to. 
>
>So at work we peer with Internode and Pipe.  My home connection is with TPG.
>I noticed on the weekend my traffic was routing asymmetrically 
>
>My home -> TPG -> Work
>Work -> Internode -> My home
>
>Found this rather strange as I thought PIPE -> TPG would be the preferred path.  So I dug into my BGP peers and looked at the tables
>
>
>What I found was rather strange from internode I had this AS path 4739,18398,7545, from Pipe I have this AS path 24130,7545,7545,7545, so for some reason TPG is AS stuffing (? Right term ? ) their prefix to Pipe.
>
>That's rather strange I think.  I don't want to have to mess too much with my BGP filters to do to any trick things, I believe I would re weight it such that TPG via pipe is the preference, but I wonder why TPG would do this.
>
>I did contact the NOC @ Pipe.. As far as they are concerned every things okay.  Let me paraphrase... 1 company 2 businesses 
>
>
>I am not sure why TPG would want to do that ?
>
>A
>
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