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Community Member

Setting up core interconnection

We're building up new datecenter network as follows:

- two interconnected cat6509/sup720 which will handle the core network (web services, mail, datacenter operation, and client access).

- two dedicated, interconnected cat6504/sup32 which will handle our business-critical applications.

The former t?pically handle many changes during their life, in term of access VLAN, ACLs, PBR, QoS.

The latter are dedicated, and, as such, they would be less involved into changes.

Furthermore, they should be able to run even if core switches are BOTH down.

STP storms should not affect the operation of these ones.

They are all connected via FO, the couples w/ a pair of Gigabit L2 etherchannel links,

and a full mesh between the two couples, to have better.

(see image)

Any suggestion on best setup for connecting the two couples, and on general configuration?

Community Member

Re: Setting up core interconnection


For interconnecting these two sets of core devices, I recommend layer 3 fiber etherchannels. Use a routing protocol like EIGRP between them.


Community Member

Re: Setting up core interconnection

Good hint.

Do you suggest doubling each connection (i.e. two ports for every interconnection?).

Should I unbalance eigrp routing, to ensure there is a primary, and a backup link, or I should let eigrp do its calculation?

Community Member

Re: Setting up core interconnection

I would start at two links per etherchannel, but if you find your core being highly utilized, you may want to increase. Since your core is a full mesh setup, EIGRP will always calculate a successor and feasible successor route. It's not recommended that you toy around with EIGRP k values, so leave it as is.


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