CCNA – IP Routing 2

Question 1

Explanation

There are no dynamic routing protocols running on Coffee router, only a default route is configured to route all traffic to 172.19.22.2 but we don’t know about this network. The correct IP address should be the IP address on the interface of Tea router which is connected to Coffee router (maybe 172.18.22.2).

Question 2

Explanation

Maybe “the most direct path available” here means via R2 because it is directly connected with the Internet while the London path needs to go through R1. So we need a command to send traffic to R2 and the correct command is “ip route 0.0.0.0 0.0.0.0 172.16.100.2″.

Question 3

Question 4

Explanation

The destination IP address 10.1.5.65 belongs to 10.1.5.64/28, 10.1.5.64/29 & 10.1.5.64/27 subnets but the “longest prefix match” algorithm will choose the most specific subnet mask -> the prefix “/29″ will be chosen to route the packet. Therefore the next-hop should be 10.1.3.3 -> C is correct.

Question 5

Explanation

While transferring data through many different networks, the source and destination IP addresses are not changed. Only the source and destination MAC addresses are changed. So in this case Host A will use the IP address of Host C and the MAC address of E0 interface to send data. When the router receives this data, it replaces the source MAC address with it own E1 interface’s MAC address and replaces the destination MAC address with Host C’s MAC address before sending to Host C -> C and F are correct.

Question 6

Question 7

Question 8

Explanation

Host A knows host B is in another network so it will send the pings to its default gateway 192.168.6.1. Host A sends a broadcast frame asking the MAC address of 192.168.6.1. These information (IP and MAC address of the default gateway) is saved in its ARP cache for later use.