will ISP peer with 2 local WAN routers?

Adam Greene maillist at webjogger.net
Fri Aug 16 21:47:04 UTC 2013


Pete,

Good point, thanks. Yes, in this case, there is some cause to believe that
the switches will prove more reliable than the routers. They're older
7200VXR's and have had some lockups in the past, possibly due to PA card /
IOS incompatibilities. 

But you're right, we are also considering accepting full or partial routes
from both providers, one provider per router, and then doing iBGP between
them to balance the load. We're thinking of deploying default routes and
HSRP to stacked 3750's for round-robin load balancing on the LAN side. 

Thanks for the help!

Adam


-----Original Message-----
From: Peter Kristolaitis [mailto:alter3d at alter3d.ca] 
Sent: Friday, August 16, 2013 5:30 PM
To: nanog at nanog.org
Subject: Re: will ISP peer with 2 local WAN routers?

But the switches themselves are a single point of failure, so if a switch
dies you still only have a single provider (assuming one switch per
provider).  ;)

All you're doing is moving the your single point of failure from the routers
to the switches, with arguably very little increase in actual reliability
(if any, depending on whether you think switches are less likely to fail
than routers).

- Pete



On 08/16/2013 05:21 PM, Adam Greene wrote:
> Thanks, Justin. Yes, we considered that option, too. But then if one 
> WAN router goes down, the customer will only have connectivity through 
> a single upstream provider. We'd prefer to maintain connectivity to 
> both even if a router fails. Switches in front of the routers is no
problem.
>
> -----Original Message-----
> From: Justin Vocke [mailto:justin.vocke at gmail.com]
> Sent: Friday, August 16, 2013 4:47 PM
> To: Adam Greene
> Cc: <nanog at nanog.org>
> Subject: Re: will ISP peer with 2 local WAN routers?
>
> The gotcha with that is then you need a switch in front of the 
> routers. I'd just setup a carrier on each router and run ibgp between.
>
> Sent from my iPhone
>
> On Aug 16, 2013, at 3:35 PM, "Adam Greene" <maillist at webjogger.net> wrote:
>
>> Hi guys,
>>
>>
>>
>> I have a customer who peers via eBGP with Lightpath aka Cablevision 
>> (AS
>> 6128) and Level3 (AS 3356) and wants to do some dual-WAN router
> redundancy.
>>
>>
>> I have heard that carriers will sometimes agree to set up a /29 WAN 
>> subnet for a customer and peer with (2) customer routers.
>>
>>
>>
>> The customer is delaying on providing me with the proper circuit ID & 
>> contact information to be able to call Lightpath and Level3 directly 
>> and find out if they will do this, so I thought of asking this list.
>>
>>
>>
>> Is anyone aware if Lightpath and Level3 will agree to something like
this?
>>
>>
>> Thanks,
>>
>> Adam
>>
>>
>>
>>
>>
>






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