Explanation/Reference:
Section: Enterprise Network Design Explanation
Explanation:
You can use StackWise to configure up to nine switches to act as a single switch. StackWise is a Cisco- proprietary Virtual Switching System (VSS) technology that is used to provide Open Systems Interconnection (OSI) Layer 2 or Layer 3 connectivity between switches so that the stack of switches acts as a single device. When a StackWise configuration is used, the failure of a single switch will not result in an outage. Instead, the other switches in the stack will compensate for the failed switch. This method of switch stacking enables the network to take advantage of many access ports on multiple interconnected physical switches, which reduces the administrative burden of managing multiple switches. In addition, StackWise enables you to add or remove physical switches without significant downtime, thereby preserving network availability and performance.
StackWise switches are connected sequentially by stack cables: the first switch is connected to the second, the second switch is connected to the third, and so on until the last switch is connected to the first.
If a stack cable is broken, the bandwidth of the stack will be reduced by 50 percent until the cable is fixed.
EtherChannel is not used to configure up to nine switches to act as a single switch. You can use EtherChannel to bundle up to eight redundant links to form a single robust link. EtherChannel can be used as an alternative to purchasing new hardware for the purpose of increasing bandwidth between two devices. For example, you could combine eight FastEthernet ports for 800 Mbps of bandwidth, eight GigabitEthernet ports for 8 Gbps of bandwidth, or eight TenGigabitEthernet ports for 80 Gbps of bandwidth. An EtherChannel link can operate at Layer 2 or Layer 3 of the OSI model. Layer 2 EtherChannel is used to connect switching ports, whereas Layer 3 EtherChannel is used to connect routing ports. When configuring Layer 2 EtherChannel, you must ensure that each link is configured to be a part of the same virtual LAN (VLAN) or as a trunk link that comprises the same range of VLANs. In addition, each link must be configured to use the same portfiltering protocol. When configuring Layer 3 EtherChannel, you must assign the same Layer 3 address to the logical interface shared by the links.
When multilayer switches are used, the logical interface will often be a switched virtual interface (SVI). In addition, links that comprise an EtherChannel are required to have matching duplex and speed settings.
Improperly configured EtherChannel links are disabled.
Hot Standby Router Protocol (HSRP) is not used to configure up to nine switches to act as a single switch.
HSRP is a Cisco-proprietary router redundancy protocol. HSRP allows several Layer 3 devices to function as a single gateway to clients? if one router fails, another router is available to forward traffic sent from the clients to the gateway IP address. Devices in an HSRP group are assigned one virtual IP address. Clients on an HSRP-enabled network send data to the virtual IP address? the data is forwarded to the active device in the group. If the active device fails, a standby device provides failover. Any additional devices in the HSRP group that are not currently designated as an active or standby router remain in listening mode until they are needed because of a failure of the active or standby device.
VLAN Trunking Protocol (VTP) is not used to configure up to nine switches to act as a single switch. VTP is a protocol that is used to manage VLAN changes and to propagate those changes over trunk ports. VTP reduces the administrative overhead of maintaining VLANs. When VTP is used, changes regarding VLAN information can be centrally configured and then propagated by VTP over trunk ports instead of manually configured on each device on the network.
Reference:
CCDA 200-310 Official Cert Guide, Chapter 4, Virtualization Technologies, pp. 153-157 Cisco: Cisco StackWise and StackWise Plus Technology