[j-nsp] Redundancy with MX

[joel jaeggli]

On 1/21/13 11:44 PM, Saku Ytti wrote:
> On (2013-01-21 21:40 +0100), Markus H wrote:
>
>> I wonder what kind of redundancy the community would prefer for
>> small-medium sized PoPs.
>>
>> a) 2xMX80
>> b) 1xMX240/480 with redundant SCB and RE
> a) no question. As long as you can live with modest RE performance of MX80.
> Routing separated two units always better than stateful single unit.
>
> Frankly, I'm not sure if dual RE even delivers better MTBF, since it does
> expose you to new issues, even outside HW failures. It probably does
> deliver you better MTTR though.
>
I would always take two routers over one router with two RE's

I have Lost RE's or crashed them in ways that a second RE helped enough 
to consider them worthwhile, and  sometimes they make upgrading easier, 
but sometimes they make it harder, and it's pretty easy to justify 
trading lower cost and less complexity for modularity.

The original poster I think raised the issue of load balancing between 
upstream(s). realistically that isn't that hard if you're architecture 
is designed to account for it.