Refer to the exhibit. In addition to static routes directing traffic to networks 10.10.0.0/16 and 10.20.0.0/16, Router HQ is also configured with the following command: ip route 0.0.0.0 0.0.0.0 serial 0/1/1  What is the purpose of this command?

The command ip route 0.0.0.0 0.0.0.0 serial 0/1/1 configured on Router HQ in the network diagram is used to set a default route. This default route is often referred to as the “gateway of last resort.” The purpose of this command is to specify that any packets with a destination network that is not found in the routing table should be forwarded to the next-hop address associated with the Serial 0/1/1 interface.

Here are the options analyzed:

• Packets from the 10.10.0.0/16 network will be forwarded to network 10.20.0.0/16, and packets from the 10.20.0.0/16 network will be forwarded to network 10.10.0.0/16.
  • This statement is incorrect because the command does not specify any conditional forwarding between the two LAN networks. It is a default route for any unknown networks, not a route between the two specified networks.
• Packets that are received from the Internet will be forwarded to one of the LANs connected to R1 or R2.
  • This statement is not entirely accurate. The command does not necessarily forward packets from the Internet to the LANs; instead, it dictates what HQ does with packets for which it has no specific route.
• Packets with a destination network that is not 10.10.0.0/16 or is not 10.20.0.0/16 or is not a directly connected network will be forwarded to the Internet.
  • This option is correct. Any packet that does not match a more specific route in the routing table of HQ, which includes the two LAN networks and any directly connected networks, will be forwarded to the next hop specified by the default route, which in this case is likely the Internet.
• Packets that are destined for networks that are not in the routing table of HQ will be dropped.
  • This statement is incorrect because the purpose of a default route is to prevent packets from being dropped when their destination networks are not in the routing table. Instead, they are sent to the default gateway.

Therefore, the purpose of the ip route 0.0.0.0 0.0.0.0 serial 0/1/1 command is to forward packets with a destination network that is not known in the router’s routing table (not 10.10.0.0/16, not 10.20.0.0/16, or not a directly connected network) to the Internet.