Cisco's Switching Model and Chassis Aggregation

beef410's version from 2018-05-21 01:48

Switch Stacking

Question Answer
StackingBundles multiple physical switches into one logical switch which can be managed as a single device.
Stack capable switchesDo not have to be stacked, they can be used as individual switches. Makes hot-swapping easier.
BenefitsScalability, fault tolerance,
FlexStack/PlusCisco's proprietary version of switch stacking, basic benefits of switch stacking are available outside of Cisco world
StackmasterFlexStack's elected master switch. Non-master switches forward all management protocol streams to the stackmaster
Stackmaster Config ChangesWhen a change is made, the master will push the config changes out.
ClusteringNot the same as stacking, only allows management of multiple switches via a single IP.
FlexStack/Plus Chassis CountFlexStack supports up to 4 2960 switches, FlexStackPlus can stack up to 8, +models are X
ModuleTo stack switches they must have the stacking module and stacking cable.
Priority(config)# switch <id> priority # will set the switches priority for stackmaster election. Highest wins.

Distribution Model

Question Answer
Three Tiered ModelCore -> Distribution -> Access
CorePrimary role is switching, avoids as much QoS/ACL's and other overhead as possible. Can still have QoS/ACLs. Network backbone, wants high-speed connections and very low latency
DistributionHigh speeds ports are desired, most routing should occur here.
AccessQoS/ACLs/Filtering/Vlans/etc run here "low cost, high switchport-to-user ratio"
Collapsed CoreDistro/Core role is combined

Chassis Aggregation

Question Answer
vs Switch StackingMain difference is this is usually done at the core layer whereas stacking is typically done at distribution. Chassis are literally 'aggregated' into what amounts to a metal box.
ConnectionsDistro switches typically have a connection with all core layer switches, when aggregated distro switches see one core switch
MECMult-chassis EtherChannel, allows a single EC from trunks to different physical (core) switches.