Name: ____________________________________________________ Alpha: _____________________

1. [10pts] Try to solve the problem manually. Consider the following:

   IP address: 210.210.210.210
   Subnet mask: 255.255.255.128
   

   • What is the network address? ______________________________________
     
     
   • Give a CIDR notation for the network. _______________________________
     
     
2. [30ts] Below left is shown the bytes of an Ethernet frame. Fill out the blank fields on the right.

   0| 08 00 27 f3 5c ca 08 00 8| 27 b3 0c 54 08 00 45 00 16| 00 24 51 a2 40 00 40 11 24| 0f cb c0 a8 ac 04 c0 a8 32| ac 06 ec d7 1a 85 00 10 40| d9 7d 51 75 61 6e 74 75 48| 6d 0a

   dst MAC addr = src MAC addr = type = version = ihl = IP packet length = (in total) protocol = (choose from TCP/UDP/ICMP) src IP = dst IP = src port = dst port = msg = b" " (in English)

3. [10pts] TRUE or FALSE questions. Circle TRUE if the given statement is true; otherwise circle FALSE.
   • TRUE / FALSE:
     ARP protocol employs IP packets to send ARP requests and responses
   • TRUE / FALSE:
     If a new transport layer protocol (apart from TCP and UDP) is invented, all routers will require modification.
   • TRUE / FALSE:
     ICMP echo packets are addressed to port 14.
   • TRUE / FALSE:
     128.128.128.0 is a valid subnet mask.
   • TRUE / FALSE:
     255.255.0.0 is a valid subnet mask.
4. [10pts] TRUE or FALSE questions. Circle TRUE if the given statement is true; otherwise circle FALSE.
   • TRUE / FALSE:
     The TCP protocol works at the network layer of the OSI model.
   • TRUE / FALSE:
     ICMP protocols work at the network layer.
   • TRUE / FALSE:
     MAC addresses are unique addresses for each network interface card (NIC).
   • TRUE / FALSE:
     MAC addresses are 4 bytes long.
   • TRUE / FALSE:
     IPv4 addresses are 4 bytes long.