Re: [pacnog] Multihoming Problem

[Gaurab Raj Upadhaya <gaurab@lahai.com>]

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Hi,

On Feb 7, 2007, at 11:07 PM, Alo Anesi wrote:

> I seem to be having some problems with my multihoming arrangement. Our
> current setup is to advertise our /20 on both of our upstream  
> providers:
> AS25625 is the primary and AS30362 is the secondary.

Got that. i only see you through AS 25625. No signs of a path through  
AS 30362.

Looking a bit further, seems like AS25625 (IP Access)  uses XO (AS  
2828) as one of their primary providers, and Qwest (AS 209) as  
alternative provider. Equal number of routes visible from both XO and  
Qwest transiting IP Access.

On comparison, HPT seems to use Time Warners Telecom (22026) as their  
primary provider. And sprint (1239) further up.

> I've checked several looking glass routers and our primary link  
> seems to
> be the best path, but I can't account for such a large amount of  
> traffic
> on our secondary.

> Any suggestions?

I guess a disproportionate number of your users are viewing CNN :-),  
but one option for you is to look at netflow stats on your outbound  
routers and see where bulk of your traffic is heading to.

Since quite a bit of 'content' these days are on some sort of CDN  
(akamai and the like), you may want to checkout which instance of the  
CDN you are getting to. Since i believe that TWT is pretty content  
heavy, you'd have to look at moving some of it off that link into  
your other link.

what is the delay like across each link.  if you ping or trace to a  
specific location in somewhere, which is faster path ? because faster  
path tends to be preferred by P2P apps.

Also, looking at your HPT configuration, what are you accepting from  
them ? only the default or some more specific routes ? Not clear from  
your config.  If you are accepting set of prefixes from HPT, then  
those will always be preferred over the default outbound over the IP  
Access default.


thanks


           -- gaurab


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gaurab at lahai dot com

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