Implementing TCP/IP

Module Overview Overview of TCP/IP Understanding IPv4 Addressing Configuring IPv4 Name Resolution 2

Overview of TCP/IP The TCP/IP Protocol Suite Protocols in the TCP/IP Suite TCP/IP Applications What Is a Socket?

The TCP/IP Protocol Suite Application HTTP FTP SMTP DNS POP3 SNMP Transport TCP UDP Internet IPv6 IPv4 ARP IGMP ICMP Network Interface Ethernet Token Ring Frame Relay ATM

Protocols in the TCP/IP Suite OSI TCP/IP TCP/IP Protocol Suite Application Application Presentation HTTP FTP SMTP DNS POP3 SNMP Session Transport Transport TCP UDP Network Internet IPv6 IPv4 ARP IGMP ICMP Data-Link Network Interface Ethernet Token Ring Frame Relay ATM Physical

TCP/IP Applications Some common application layer protocols are: HTTP/HTTPS RPC over HTTP FTP RDP SMB SMTP POP3

What Is a Socket? TCP/IP Protocol Suite HTTP (80) HTTPS (443) POP3 (110) SMTP (25) DNS (53) FTP (21) TCP/UDP IPv4 IPv6

Understanding IPv4 Addressing How Dotted Decimal Notation Relates to Binary Numbers IPv4 Addressing Simple IPv4 Implementations More Complex IPv4 Implementations How Bits Are Used in a Subnet Mask Implementing an IPv4 Subnetting Scheme Determining Subnet Addresses Determining Host Addresses

How Dotted Decimal Notation Relates to Binary Numbers Course 6420A 8-Bit Octet Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 27 26 25 24 23 22 21 20 128 64 32 16 8 4 2 1 Decimal Value

IPv4 Addressing An IPv4 configuration identifies a computer to other computers on a network IP Address 192.168.2.182 255.255.255.0 IP Address 192.168.2.180 255.255.255.0 IP Address 192.168.2.181 255.255.255.0 Subnet 1 Default gateway defines the preferred router IP Address 192.168.1.201 255.255.255.0 IP Address 192.168.1.202 255.255.255.0 IP Address 192.168.1.200 255.255.255.0 Subnet 2 Dotted decimal representation of the address and subnet mask

Simple IPv4 Implementations Network ID Host ID 1 1 0 x w y z 1 0 Class A Large Network Class B Medium Network Class C Small Network

More Complex IPv4 Implementations 172.16.16.0/22 172.16.17.1 172.16.17.0/24 172.16.20.0/22 172.16.17.254 172.16.16.1/20 172.16.24.0/22 172.16.18.0/24 172.16.28.0/22

How Bits Are Used in a Subnet Mask Course 6420A Class B Address with Subnet Number of Subnets 254 128 254 64 32 16 4 8 2 Network ID Subnet ID Host ID 1 Number of Hosts 32,512 65,534 16,256 254 8,128 4,064 1,016 2,032 254 508

Implementing an IPv4 Subnetting Scheme When you subdivide a network into subnets, create a unique ID for each subnet derived from the main network ID By using subnets, you can: Use a single network address across multiple locations Reduce network congestion by segmenting traffic Overcome limitations of current technologies

Determining Subnet Addresses When determining subnet addresses you should: Choose the number of subnet bits based on the number of subnets required Use 2n to determine the number of subnets available from n bits For five locations, the following three subnet bits are required: 5 locations = 5 subnets required 22 = 4 subnets (not enough) 23 = 8 subnets

Determining Host Addresses When determining host addresses you should: Choose the number of host bits based on the number of hosts required on each subnet Use 2n-2 to determine the number of hosts available on each subnet available from n bits For subnets with 100 hosts, seven the following host bits are required: 26-2 = 62 hosts (not enough) 27-2 = 126 hosts

Configuring IPv4 Public and Private IPv4 Addresses Automatic IPv4 Configuration

Public and Private IPv4 Addresses Required by devices and hosts that connect directly to the Internet Must be globally unique Routable on the Internet Must be assigned by IANA Nonroutable on the Internet Can be locally assigned by organization Must be translated to access the Internet

Automatic IPv4 Configuration APIPA: Is used if a DHCP server cannot be contacted Assigns IP addresses on the 169.254.0.0/16 network Cannot be used with: Active Directory Internet connectivity Multiple subnets DNS or WINS servers

Name Resolution Configuring a Computer Name What Is DNS? DNS Zones and Records How Internet DNS Names Are Resolved What Is WINS? The NetBIOS Name Resolution Process How a Client Resolves a Name

Configuring a Computer Name Description Host name Up to 255 characters in length Can contain alphabetic and numeric characters, periods, and hyphens Part of FQDN NetBIOS name Represent a single computer or group of computers 15 characters used for the name 16th character identifies service Flat namespace

What Is DNS? DNS is a service that manages the resolution of host names to IP addresses: Resolve host names to IP addresses Locate domain controllers and global catalog servers Used to resolve IP addresses to host names Used to locate mail servers during e-mail deliver

DNS Zones and Records A DNS zone is a specific portion of DNS namespace that can contain DNS records Records in forward lookup zones include: A SRV MX CNAME Records in reverse lookup zones include: PTR

How Internet DNS Names Are Resolved Microsoft.com DNS Server .com DNS Server What is the IP address of www.microsoft.com? Root DNS Server Local DNS Server 207.46.230.219 Workstation

What Is WINS? Queries a WINS server NetBIOS Name Registration Query ? OK Payroll WINS Server Queries a WINS server 1 Determines whether name is in use 2 If not in use, then registers the NetBIOS name and associated IP address 3

The NetBIOS Name Resolution Process DNS Server 7 NetBIOS Name Cache 1 DNS Resolver Cache 6 Local Host Name 5 WINS Server 2 Lmhosts File 4 Broadcast 3

How a Client Resolves a Name NetBIOS Name Cache 4 WINS Server Broadcast 6 DNS Resolver Cache 2 Local Host Name 1 Lmhosts File 7 DNS Server 3 5

Summary Overview of TCP/IP Understanding IPv4 Addressing Configuring IPv4 Name Resolution 28