Exam 350-401 topic 1 question 513 discussion

B. is ONLY valid if the "other" router has preemption enabled. How can anybody tell? D. wrong E. wrong Correct answers A. since the local router has preemption enabled with a minimum 5 sec. delay it becomes the active router. C. Obviously the virtual IP is 10.1.1.1

I do not think A can be correct because the router would not be considered down until the 10 second hold time has elapsed and only then would the 5 second preempt start. A mentions time after a missed hello not after a down state. B+C are what I would pick.

B is incorrect. A Router with a higher IP address and same HSRP priority becomes the active role "only if" it has also the preemption enabled. A is correct because the actual Stanby , if it's not receiving 3 consecutive hellos, it becomes the new active ( so more then 5 sec)

The higher IP address is only used as a tiebreaker when two or more routers have the same priority during the initial election process.Once the active router is chosen, a router with a higher IP address cannot preempt the active router unless preemption is enabled and it has a higher priority.

C. The virtual IP address of the HSRP group is 10.1.1.1. The exhibit clearly states Virtual IP address is 10.1.1.1, which indicates that this is the virtual IP used by the HSRP group. D. The hello and hold timers are set to custom values. HSRP Version 2!

In HSRPv2 preemption is enabled by default. So the answer is correct.

Option A is incorrect. The hold timer is 10 seconds, which means the local (standby) router will take over only if it doesn't receive a hello message from the active router within 10 seconds. With the 5 sec extra preemption delay, the router will wait 5 more seconds before becoming an active router (10 + 5 = 15 seconds Total). Option D is incorrect. We're using the default hello (3 seconds,) and the dead timers (10 seconds). Option E is incorrect. The local device has a lower priority than the active router (100 < 255); the router with the higher priority value wins. Option B is correct, preemption is enabled by default in HSRP v2, the one used in the exhibit. Option C is correct as mentioned by the exhibit "virtual IP address is 10.1.1.1'

how can it not be a?

B and C are correct

Here is a LAB (eve-ng) verification of answer A: R3#show standby Ethernet0/0 - Group 2 (version 2) State is Standby 4 state changes, last state change 00:03:31 Virtual IP address is 10.1.1.1 Active virtual MAC address is 0000.0c9f.f002 Local virtual MAC address is 0000.0c9f.f002 (v2 default) Hello time 3 sec, hold time 10 sec Next hello sent in 2.512 secs Preemption enabled Active router is 10.1.1.2, priority 255 (expires in 9.120 sec) MAC address is aabb.cc00.7000 Standby router is local Priority 100 (default 100) Group name is "hsrp-Et0/0-2" (default)

Confirmed in CML A is the answer. We do not have enough info for B to be accurate. I killed the linke from R1 to R2 and R2 took over even with priority of 100 over 255. Simply because preempt is enabled on R2 Its easy for everyone here to talk and link articles, but have you guys actually labbed this stuff to find out if it practically works? Too many book worms around here. HSRP_R1(config-if)#do show standby GigabitEthernet0/1 - Group 0 (version 2) State is Standby 12 state changes, last state change 00:00:41 Virtual IP address is 10.10.1.1 Active virtual MAC address is 0000.0c9f.f000 Local virtual MAC address is 0000.0c9f.f000 (v2 default) Hello time 3 sec, hold time 10 sec Next hello sent in 0.048 secs Preemption disabled Active router is 10.10.1.3, priority 100 (expires in 9.872 sec) MAC address is 5254.001e.efc3 Standby router is local Priority 255 (configured 255) Group name is "hsrp-Gi0/1-0" (default)

Not A: hold timer is 10 seconds (not 5 sec)

B does seem to be the best 2nd answer but the "5 seconds later" is a problem because we don't know what the preempt settings are on the other routers. We can only assume all have preempt enabled with 5 second delay.

BC is correct

HSRP uses two types of timers — hello and hold timers — to ensure redundancy among routers. The hello timer sends multicasts, or hello packets that broadcast status and priorities every three seconds. By default, if you don't tune in anything, the active and standby routers will say "hello" to each other once every three seconds. The hold timer tells the standby router when to take over. The standby router becomes active when it hasn't received a hello packet from the primary router in 10 seconds. So, worst case scenario, you've got 10 seconds before a standby router takes over and the timer settings can be lowered. A- Are wrong because Standby router only take over after 10 sec not 5 sec base on default hello timer and hold timer

its deffinitely BC

Not enough information to deduce that B will be true. Preemption is required and that's not indicated.