Section 5 – Implement High Availability, given a network design and a set of requirements
QUESTION NO: 51
In what three states is it possible for an HSRP router to be in? (Select three)
A. Standby
B. Established
C. Active
D. Idle
E. Backup
F. Init
Answer: ACF
Explanation:
With HSRP, a set of routers work together to present the illusion of a single virtual router to the hosts on the LAN. This set is known as an HSRP group or a standby group. A single router elected from the group is responsible for forwarding the packets that hosts send to the virtual router. This router is known as the Active router. Another router is elected as the Standby router.
In the event that the Active router fails, the Standby assumes the packet-forwarding duties of theActive router. Although an arbitrary number of routers may run HSRP, only the Active router forwards the packets sent to the virtual router. Before a router becomes the active or standby router, it will be in the Init (initial) state.
QUESTION NO: 52
Refer to the exhibit. Assume that Host A can ping the corporate headquarters and that HSRP is configured on DSw1, which is then reloaded. Assume that DSw2 is then configured and reloaded. On the basis of this information, what conclusion can be drawn?
A. DSw1 will be the active router because it has the lower priority configured.
B. DSw1 will be the standby router because it has the lower IP address.
C. DSw2 will be the active router because it booted last.
D. DSw1 will be the active router because it booted first.
E. DSw2 will be the active router because it has the higher priority that is configured.
F. DSw2 will be the standby router because it has the higher IP address.
Answer: D
Explanation:
Even though router Company2 has a higher priority, it will not become the active router because the HSRP preemption was not configured. Since the “standby 62 preempt” command was not configured, the first HSRP router to boot up will become the active router and remain the active router even when another device with a higher priority is added.
QUESTION NO: 53
Refer to the exhibit. HSRP has been configured and Link A is the primary route to router R4.
When Link A fails, router R2 (Link B) becomes the active router. Which router will assume the active role when Link A becomes operational again?”
A. The primary router R1 will reassume the active role when it comes back online.
B. The standby router R2 will remain active and will forward the active role to router R1 only in the event of its own failure.
C. The standby router R2 will remain active and will forward the active role to router R1 only in the event of Link B failure.
D. The third member of the HSRP group, router R3, will take over the active role only in event of router R2 failure.
Answer: A
Explanation:
HSRP election is based on a priority value (0 to 255) that is configured on each router in the group. By default, the priority is 100. The router with the highest priority value (255 is highest) becomes the active router for the group. If all router priorities are equal or set to the default value, the router with the highest IP address on the HSRP interface becomes the active router. To set the priority, use the following interface configuration command:
Switch(config-if)# standby group priority priority
When HSRP is configured on an interface, the router progresses through a series of states before becoming active. This forces a router to listen for others in a group and see where it fits into the pecking order. The HSRP state sequence is Disabled, Init, Listen, Speak, Standby, and, finally, Active.
Only the standby (second highest priority) router monitors the hello messages from the active router. By default, hellos are sent every 3 seconds. If hellos are missed for the duration of the hold time timer (default 10 seconds, or 3 times the hello timer), the active router is presumed down.
The standby router is then clear to assume the active role. If other routers are sitting in the Listen state, the next-highest priority router is allowed to become the new standby router.
QUESTION NO: 54
Regarding high availability, with the MAC address 0000.0c07.ac03, what does the “03” represent?
A. The VRRP group number
B. The GLBP group number
C. The type of encapsulation
D. The HSRP router number
E. The VRRP group number
F. The HSRP group number
G. The active router number
Answer: F
Explanation:
Each router keeps a unique MAC address for its interface. This MAC address is always associated with the unique IP address configured on the interface. For the virtual router address, HSRP defines a special MAC address of the form 0000.0c07.acxx, where xx represents the HSRP group number as a two-digit hex value. For example, HSRP Group 1 appears as 0000.0c07.ac01, HSRP Group 16 appears as 0000.0c07.ac10.
QUESTION NO: 55
Which two statements are true about HSRP, VRRP, and GLBP? (Choose two.)
A.GLBP allows for router load balancing of traffic from a network segment without the different host IP configurations required to achieve the same results with HSRP.
B.GLBP allows for router load balancing of traffic from a network segment by utilizing the creation of multiple standby groups.
C.GLBP and VRRP allow for MD5 authentication, whereas HSRP does not.
D.Unlike HSRP and VRRP, GLBP allows automatic selection and simultaneous use of multiple available gateways.
E.HSRP allows for multiple upstream active links being simultaneously used, whereas GLBP does not.
Answer: A D
