Refer to the exhibit. HostA cannot ping HostB. Assuming routing is properly configured, what could
be the cause of this problem?
A.
The address of SwitchA is a subnet address.
B.
HostA is not on the same subnet as its default gateway.
C.
The Fa0/0 interface on RouterA is on a subnet that can’t be used.
D.
The Fa0/0 interface on RouterB is using a broadcast address.
E.
The serial interfaces of the routers are not on the same subnet.
Explanation:
A subnet mask of /27 (255.255.255.224) will have 3 bits used for the network portion and 5 bits for
the host portion. This will create 2^3 = 8 networks with 2^5 = 32 hosts per network. From this we
know that the number of subnets will be a multiple of 32, making the subnets:
1. 192.168.1.0
2. 192.168.1.32
3. 192.168.1.64
4. 192.168.1.96
5. 192.168.1.128
6. 192.168.1.160
7. 192.168.1.192
8. 192.168.1.224
From this, we can see that the serial interface of router A lies within the second network shown
above while the serial interface of Router B lies within the third. For directly connected routers
they should be in the same IP subnet.