1. Module 8: Networking Services
3.5 Understand Networking Services
3.4 Understand Names Resolution

2. Agenda 1
Common Networking Services 2
Name Resolution Techniques

3. Common Networking Services

4. DHCP
Dynamic Host Configuration Protocol (DHCP) is a client/server protocol that enables configured client computers to obtain IP addresses automatically
The IP information obtained might include the following:
IP addresses
Subnet masks
Gateway addresses
DNS server addresses
Other advanced options
The DHCP Server service provides the following benefits:
Reliable IP address configuration
Reduced network administration

5. DHCP Server
Before a DHCP server can start leasing IP addresses to client computers, the following steps must be performed:
Install the DHCP service
Configure an IP scope
Activate the scope
Authorize the server
Configure advanced IP options (optional)

6. DORA DHCP sessions use a four-step process known as DORA.
Discovery: The client sends a broadcast to the network to find a DHCP server
Offer: The DHCP server sends a unicast “offering” of an IP address to the client
Request: The client broadcasts to all servers that it has accepted the offer
Acknowledge: The DHCP server sends a final unicast to the client that includes the IP information the client will use
DHCP utilizes ports 67 and 68

7. APIPA
Assigns unique IP addresses within the APIPA range when no DHCP server is available
APIPA can get in the way of a client obtaining an IP address properly (e.g., when a client attempts to obtain an IP address from a DHCP server, but the DHCP server is too busy)
Will prevent a computer from accessing the Internet
Can communicate with other devices on a LAN

8. Remote Desktop Services (RDS)
A type of thin-client terminal server computing
RDS enables virtual desktop infrastructure (VDI), session-based desktops, and applications, allowing users to work anywhere
Thin-client computers and PCs can connect to servers running Remote Desktop Services
Bing up Server PosterPedia

9. Name Resolution Techniques

10. Domain Name System (DNS)
DNS is a worldwide service that resolves host names to IP addresses
DNS architecture is a hierarchical distributed database and an associated set of protocols that define:
A mechanism for querying and updating the database
A mechanism for replicating the information in the database among servers
DNS is part of the application layer of the TCP/IP reference model
DNS servers use inbound port 53 to accept name resolution requests

11. How does DNS work?
Clients access libraries called resolvers to perform DNS queries
There are two types of DNS queries:
Recursive: Server responds with destination IP address or an error message
Iterative: Server points client to a different DNS server

12. WINS
Windows Internet Name Service (WINS) is a service that resolves NetBIOS names to IP addresses
WINS is required for any environment in which users access resources that have NetBIOS names
It is Microsoft’s version of the NetBIOS Name Service (NBNS) combined with a name server
If you do not use WINS in such a network, you cannot connect to a remote network resource by using its NetBIOS name unless you use Lmhosts files, and you might be unable to establish file and print sharing connections

13. Summary 1
Common Networking Services 2
Name Resolution Techniques