Question 2
You were given the address 223.6.14.6/29 by your ISP to assign to your router’s interface. They have also given you the default gateway address of 223.6.14.7. After you have configured the address, the router is unable to ping any remote devices. What is preventing the router from pinging remote devices?
A. The default gateway is not an address on this subnet.
B. The default gateway is the broadcast address for this subnet.
C. The IP address is the broadcast address for this subnet.
D. The IP address is an invalid class D multicast address.
Answer: B
Explanation
Again use the Cram table:
Bit Value
128
64
32
16
8
4
2
1
Bit Borrowed
1
2
3
4
5
6
7
8
Usable host address
126
62
30
14
6
2
Subnet Mask
128
192
224
240
248
252
255
256
Subnet Prefix/CIDR
/25
/26
/27
/28
/29
/30
For the network 223.6.14.6/29 which mask will be 255.255.255.248. This offers only 6 usable host addresses.
So the Network address: 223.6.14.0
Usable host IP address: 223.6.14.1 - 6
Broadcast address: 223.6.14.7
Question 3
Refer to the exhibit below.
According to the routing table, where will the router send a packet destined for 10.1.6.65?
Network
Interface
Next-hop
10.1.1.0/24
e0
directly connected
10.1.2.0/24
e1
directly connected
10.1.3.0/25
s0
directly connected
10.1.4.0/24
s1
directly connected
10.1.6.0/24
e0
10.1.1.2
10.1.6.64/28
e1
10.1.2.2
10.1.6.64/29
s0
10.1.3.3
10.1.6.64/27
s1
10.1.4.4
A. 10.1.1.2
B. 10.1.2.2
C. 10.1.3.3
D. 10.1.4.4
Answer: C
Explanation
If you look at the table, The destination IP address 10.1.6.65 belongs to 10.1.6.64/28, 10.1.6.64/29 & 10.1.6.64/27 subnets. But the subnet with the longest prefix match will be chosen. In this case, the next hop configured on the router will be where the packet will be sent.
- See more at: http://www.orbitco-ccna-pastquestions.com/CCNA-%E2%80%93-Common-Subnetting-Questions.php#sthash.j9HG665W.dpuf