Multi-layer Switching at the Core?

in CCDA & CCDP
From Diane Teare book:
Do people really use multi-layer switches at the core?
Because core devices are responsible for accommodating failures by rerouting traffic and
responding quickly to network topology changes, and because performance for routing in the
core with a multilayer switch incurs no cost, most implementations have multilayer switching
in the core layer. The core layer can therefore more readily implement scalable protocols and
technologies, alternate paths, and load balancing.
Do people really use multi-layer switches at the core?
Comments
Simple answer is yes.
We use layer 2 VLAN separation for server access ports and OSPF to route traffic from the core switch to i.e. the WAN core router / WAN sites. Nortel Passport core switches talking to Cisco routers hence the OSPF protocol selection and not EIGRP.
CCNA Security | GSEC |GCFW | GCIH | GCIA
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http://twitter.com/paul_bosworth
Blog: http://www.infosiege.net/
Junipers are great BGP routers. Generally they're used in the core when BGP is. At my last job we used Juniper M10's at the edge for BGP then interfaced them with our core as a peering module. We had the Junipers configured as a route reflector with two clients (each client was an OC12 to a different upstream peer). All IP traffic would be on one vlan with a default route pointing at the Juniper BGP route reflector. From there best-route decisions would happen. This is a pretty standard multi-homing scenario and solution when the ISP/network in question isn't a carrier.
CCNA Security | GSEC |GCFW | GCIH | GCIA
[email protected]
http://twitter.com/paul_bosworth
Blog: http://www.infosiege.net/