Re: [nznog] Help / Advise tweaking BGP settings

WXC have a public looking glass/route server. just telnet to route-server.wxnz.net glhf On Fri, Nov 1, 2013 at 5:00 PM, Nathan Ward wrote:

On 1/11/2013, at 10:17 AM, Alexander Neilson wrote:

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Hey All

We have recently made some major changes at $DAYJOB with our connectivity to the outside world and our peering.

One of the things we have taken on is a 1Gbps APE peering port and Upgraded out WIX port to 100Mbps.

While I find often our inbound traffic takes a fairly efficient path (usually - tho $TRANSITPROVIDER seems to cut prepends and possibly even disaggregates some prefixes (tho this could be something hanging around)) our outbound does seem to be less efficient, especially where APE is concerned.

It would be very unusual for a transit provider to deaggregate your prefixes, or tamper with the AS_PATH you present them. Have you confirmed your assumptions by looking at some international looking glasses? I like route-views.oregon-ix.net (telnet).

http://bgplay.routeviews.org/ is also a very useful resource, if you have Java installed :-)

Another tip, get a subscription to http://www.bgpmon.net/

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I am currently testing an adaption where I only accept shorter prefixes from $TRANSITPROVIDER and a default route (to avoid blackholing) the domestic transit doesn’t have a “default route” option and I want to avoid pushing domestic traffic over International if it only has a long prefix to match and isn’t peered.

Would anyone be willing to provide me some tips / tricks / advise / examples of what they do with BGP (or some good resources) that I can use to improve the routing table I use in the network?

What are you looking to do? Reduce your routing table size?

I haven't come across any instances where choosing a domestic route instead of an international one caused a problem, in a number of years. Last time I remember it, someone had taken a /24 out of a University /16 to Germany, and it caused problems for the individual using it there. Given that, maybe you'd do well running default+domestic?

I've got a few pretty complete NZ+international routing tables, I'm sure it wouldn't be hard to see if there's any international prefixes that are subnets of NZ prefixes. In fact, tonight after I've had a beer I'm going to give it a go.

It's hard to say without the variables in this email being expanded, BTW :-)

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Also does anyone have NZ Provider looking glass servers (not the NZIX as I know and use them) where I can see how other domestic providers see my announced routes and how it appears to them (so I can make changes and test but also see what I am being seen as)?

I tend to ask people what they see - I'm not aware of any public LGs in NZ. Happy to look on AS9500 and another AS hanging off Vocus/Maxnet which I've forgotten the number for, if you give me some prefixes.

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Thank you very much in advance for any help. Off list replies are welcomed and possibly better to avoid clogging up the list if people think this is too basic a request for here.

-- Nathan Ward

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