1 NET 431 ADVANCED NET SERVICES Networks and

1 NET 431: ADVANCED NET SERVICES Networks and Communication Department Tutorial 3

2 Q 1: DHCP uses several messages such as DHCPREQUEST, DHCPOFFER, DHCPACK, , and DHCPDISCOVER. Find the purpose of these messages. 25 -Nov-20 Networks and Communication Department

3 � DHCPDiscover Broadcast by a DHCP client The DHCPDiscover message requests IP address information from a DHCP server. � DHCPOffer Broadcast by each DHCP server that receives the client DHCPDiscover message and has an IP address configuration to offer to the client. The DHCPOffer message contains an unleased IP address and additional TCP/IP configuration information. 25 -Nov-20 Networks and Communication Department

4 � DHCPRequest Broadcast by a DHCP client after it selects a DHCPOffer. The DHCPRequest message contains the IP address from the DHCPOffer that it selected. � DHCPAck Broadcast by a DHCP server to a DHCP client acknowledging the DHCPRequest message. At this time, the server also forwards any options. Upon receipt of the DHCPAck, the client can use the leased IP address to participate in the 25 -Nov-20 Networks and Communication Department TCP/IP network

5 Q 2: What is a DHCP lease? A DHCP lease is the amount of time that the DHCP server grants to the DHCP client permission to use a particular IP address. A typical server allows its administrator to set the lease time. 25 -Nov-20 Networks and Communication Department

6 Q 3: Refer to the exhibit. Which rule does the DHCP server use when there is an IP address conflict? Ans: Assign BAD-Address and The address is removed from the pool until the conflict is resolved. 25 -Nov-20 Networks and Communication Department

7 Q 4: Determine which of the following is an FQDN and which is a PQDN. a. xxx b. xxx. yyy. a. PQDN c. xxx. yyy. net b. FQDN d. zzz. yyy. xxx. edu. c. PQDN d. FQDN e. mil. e. FQDN f. edu. g. PQDN g. xxx. yyy. net h. PQDN h. zzz. yyy. xxx. edu 25 -Nov-20 Networks and Communication Department

8 Q 5: If a DNS domain name is voyager. fhda. edu, how many labels are involved here? How many levels of hierarchy? There are three labels but four levels of hierarchy since the root is considered a level. 25 -Nov-20 Networks and Communication Department

9 Q 6: Is a PQDN necessarily shorter than the corresponding FQDN? It is always shorter by at least a dot. 25 -Nov-20 Networks and Communication Department

10 Q 7: A domain name is hello. customer. info. Is this a generic domain or a country domain? This is a generic domain. 25 -Nov-20 Networks and Communication Department

11 Q 8: How does caching increase the efficiency of name resolution? Caching reduces the search time for a name. 25 -Nov-20 Networks and Communication Department

12 Q 9: What is the purpose of the inverse domain? The inverse domain maps an address to a name. 25 -Nov-20 Networks and Communication Department

13 Q&A 25 -Nov-20 Networks and Communication Department