[olug-colo] The Legal Mumbo-Jumbo

Dan Clough dclough at gmail.com
Mon Apr 6 18:04:21 EDT 2009


Sounds good.

Although, if you prefer working with IOS, we could replace that 4912G
with a Catalyst 4000.  As you definitely know, the 4000s/4500s with
the SupII+ modules and up all run IOS.  If we can snag a 4000 with IOS
and get the GBIC modules we would have a nice L3-capable distribution
setup.

If space allows we'll most likely stick the router and distribution
switches in a two-post to save precious rackspace.  This will allow us
to move up to the bigger, more expandable setups like the 4000s and
make the networking kit more accessible.

On Mon, Apr 6, 2009 at 4:50 PM, Phil Brutsche <phil at brutsche.us> wrote:
> A 4912G is a 1.5U device, so basically 2U. It's not too horribly big.
>
> Redundancy: I don't think it's feasible at this point in time.
>
> IMO the only way redundant switches would be feasible would be to have a
> pair of L3 switches at the entry point from the ISP with support from
> the ISP, in the form of dual internet feeds - redundant aggregation
> switches don't help any if you have a single point of failure further
> upstream, and redundant routers don't help any if only one can be
> connected to the ISP at once.
>
> I would envision infrastructure redundancy like so:
>
> Redundant L3 switches connected to the ISP, each with it's own 'net
> connection.
>
> The redundant L3 switches would then feed redundant 4912Gs. Each 48-port
> switch would have a fiber link to the each 4912G.
>
> The Catalyst 3550s support Cisco's HSRP (hot standby router protocol),
> so it's at least feasible there. IEEE spanning trees make redundant
> aggregation switches a snap.
>
> Since we'll be operating - at least initially - on a shoestring budget
> and on a best-effort basis I think the best we can offer is cold spares
> and same-day recovery from hardware failure.


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