08-11-2023, 11:12 PM
TL;DR I think the right answers are:
I believe one of the answers and the explanation is incorrect. Here is why . . .
One of the answers looks fine to me:
ipv6 route 2001:db8:23::/64 fd00:12::2
As does the corresponding explanation:
"The above static route fulfills the requirement that packets toward the entire network 2001:db8:23::/64 must be forwarded through router R2."
This answer looks wrong to me:
ipv6 route 2001:db8:23::14/64 fd00:12::2 200
And the explanation doesn't make sense:
"The router will not use this route through R2 due to the higher AD value but will use the route through R3. So this entry fulfills the requirement that packets toward host 2001:db8:23::14 preferably must be routed through R3."
The destination in the second answer is effectively the same as the destination in the first answer, due to the /64 prefix. The host ID of ::14 is ignored completely by the router, making the statement nothing but a repetition of the first answer, except with an AD of 200. The result of this would be that *all* traffic is routed through R3 unless the interface goes down.
The answer that looks right to me is:
ipv6 route 2001:db8:23::14/128 fd00:13::3
I haven't popped this into PacketTracer to verify it yet, but if the two answers I think are right are used, the result should be that 2 routes are added to the routing table such as:
S 2001:db8:23::14/128 [1/0] fd00:13::3
S 2001:db8:23::/64 [1/0] fd00:12::2
Traffic destined for 2001:db8:23::14 would be routed via fd00:13::3 because the route has the longest matching prefix, but if the route went away it would fail over to the route via 2001:db8:12::2 because it still matches the /64 prefix.
However, traffic for the rest of the 2001:db8:23::/64 network would never be routed via fd00:13::3, absent another static route or a configured dynamic protocol.
- ipv6 route 2001:db8:23::/64 fd00:12::2
- ipv6 route 2001:db8:23::14/128 fd00:13::3
I believe one of the answers and the explanation is incorrect. Here is why . . .
One of the answers looks fine to me:
ipv6 route 2001:db8:23::/64 fd00:12::2
As does the corresponding explanation:
"The above static route fulfills the requirement that packets toward the entire network 2001:db8:23::/64 must be forwarded through router R2."
This answer looks wrong to me:
ipv6 route 2001:db8:23::14/64 fd00:12::2 200
And the explanation doesn't make sense:
"The router will not use this route through R2 due to the higher AD value but will use the route through R3. So this entry fulfills the requirement that packets toward host 2001:db8:23::14 preferably must be routed through R3."
The destination in the second answer is effectively the same as the destination in the first answer, due to the /64 prefix. The host ID of ::14 is ignored completely by the router, making the statement nothing but a repetition of the first answer, except with an AD of 200. The result of this would be that *all* traffic is routed through R3 unless the interface goes down.
The answer that looks right to me is:
ipv6 route 2001:db8:23::14/128 fd00:13::3
I haven't popped this into PacketTracer to verify it yet, but if the two answers I think are right are used, the result should be that 2 routes are added to the routing table such as:
S 2001:db8:23::14/128 [1/0] fd00:13::3
S 2001:db8:23::/64 [1/0] fd00:12::2
Traffic destined for 2001:db8:23::14 would be routed via fd00:13::3 because the route has the longest matching prefix, but if the route went away it would fail over to the route via 2001:db8:12::2 because it still matches the /64 prefix.
However, traffic for the rest of the 2001:db8:23::/64 network would never be routed via fd00:13::3, absent another static route or a configured dynamic protocol.
