[c-nsp] Selecting an eBGP destination based on the source network.

[David Sinn]

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Another way to do what sounds to be sourced based routing would be to  
look at multiple route tables.  So deploy a VPN/VRF model with a  
route table mapping to each of the customer classes you have.  Within  
the VPN/VRF you have the routes prioritize in the way you detail below.

David

On Dec 14, 2006, at 2:55 PM, Rick Ernst wrote:

> It's a forwarding decision.
>
> "Customer class A" would prefer high-speed/high-quality outbound  
> links and
> fall back to low-speed/low-cost links in case of failure, while  
> "Customer
> class B" would prefer the low-speed/low-cost links and fall back to  
> the
> high-speed/high-quality links.
>
> The key would be determining the destination based on source  
> network, and
> my initial thought was doing something with next-hop, but that  
> raises a
> possible reachability problem if the next-hop isn't available.
>
> Thanks!
>
> On Thu, December 14, 2006 14:47, Bruce Pinsky wrote:
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>> Rick Ernst wrote:
>>>
>>> I'm trying to find some way to prefer an outbound eBGP peer based  
>>> on the
>>> internal source network.  The idea is to prefer a particular  
>>> provider
>>> for
>>> specific source networks due to SLA, performance, or other issues.
>>>
>>> I've looked at conditional announcements and set ip next-hop, but  
>>> they
>>> don't seem to be designed for what I'm looking at.
>>>
>>> Am I missing something obvious, or is there some other way to  
>>> accomplish
>>> this?
>>> It's easy to modify the inbound path based on outbound  
>>> announcements,
>>> but
>>> once the multiple eBGP routes have made it into the (redundant)  
>>> core (RR
>>> server) FIB, there is no control over where the traffic goes.
>>>
>>
>> Are you trying to alter the forwarding decision or the route  
>> selection?
>>
>> My take is that you want to make forwarding decisions based on source
>> address rather than destination address.  In that case, you would  
>> want
>> Policy Based Routing.  So you would set the IP next-hop based on the
>> source
>> address.
>>
>> If you are trying to alter the route selection based on some  
>> criteria like
>> performance or SLAs, you may be able to do something with  
>> Optimized Edge
>> Routing.
>>
>> - --
>> =========
>> bep
>>
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>
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