Specifications

CHAPTER 5
Implementing High Availability
Using Nonchassis Based Access Switches
Using more than one stand-alone switch, such as the Cisco 3560 or 3750, in an access closet requires special design
consideration. You can either daisy-chain the switches or use the Cisco Stackwise technology. When you daisy-chain
switches, the top and bottom members of the chain typically uplink to one distribution switch each. You must add a link
(or loopback cable) between the top and bottom switch. Otherwise, a failure in the link between two access switches
might cause return traffic to be blackholed. Alternatively you can configure the link between the distribution switches as
an L2 trunk.
Stackwise switches enable you to manage each group of access switches as one. Two stack member switches uplink to
the distribution switches. Special cables connect the switches, and you should still connect the top and bottom members
of the stack using a Stackwise cable. The link between distribution switches can then be an L3 link without worry of
blackholing return traffic.
Network Management for High Availability
Network administrators use network management tools:
n To verify network performance
n To characterize, or baseline, network performance
n To understand amount and direction of traffic flow within the network
n To troubleshoot network problems
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CCNP SWITCH 642-813 Quick Reference by Denise Donohue
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