IP Addresses

1
IP Addresses
2
Flat vs. Hierarchical Addresses

• A flat address cannot be subdivided into parts
• Computer names in a NT domain
• Unless you create a naming scheme that imposes a
  structure (i.e. KCFIN01, KCFIN02, NYFIN01)
• A hierarchical address can be subdivided
• Postal addresses
• zip code, state city, street, number

3
IP Addresses

• 32 bit Addresses
• Dotted decimal 130.57.30.56
• Binary 10000010.00111001.00011110.00111000
• Hex 82 39 1E 38
• IP Addresses have two levels
• Network address
• Node (host) address

4
Host Names

• Host names are an hierarchical naming scheme used
  for the benefits of humans
• HostName.SubdomainName.DomainName.TopLevelDomain
• This is a Fully Qualified Domain Name (FQDN)
• Host names must be resolved into IP addresses
  before IP can use them

5
Host Names

• Top-level Domain Names (e.g. COM, EDU)
• Descriptive categories created by Internet
  authorities
• Domain name (e.g. UCF)
• Name chosen by an individual or organization
• Must be registered with the InterNIC
• Subdomains (e.g. BUS)
• Further descriptive categories created by
  organizations
• May have multiple subdomains
• Host Name (e.g. WWW, SYSTEMS)
• The name given to an individual host

6
Network Classes
7
Reserved Addresses

• Network all 0s
• This host
• e.g. 0.0.25.1
• Network all 1s
• All networks
• e.g. 255.255.25.1
• Entire address 1s
• All hosts on this network because it will not be
  routed
• e.g. 255.255.255.255

• Network 127
• Loopback
• Host all 0s
• Identifies a network
• e.g. 129.130.0.0
• Host all 1s
• All hosts on indicated network
• e.g. 129.130.255.255

8
Obtaining IP Addresses

• Your upstream WAN provider (ISP or NSP)
• Your providers upstream provider
• A network number registry
• Network addresses obtained directly from a
  registry are not guaranteed to be globally
  routable

9
Address Registries

• Internet addressing comes under the authority of
  the Internet Corporation for Assigned Names and
  Numbers (ICANN)
• www.icann.org
• Addresses are obtained from regional registries
• American Registry for Internet Numbers (ARIN)
• www.arin.net
• Réseaux IP Européens (RIPE)
• www.ripe.net
• Asia Pacific Network Information Center (APNIC)
• www.apnic.net

10
Host Configuration

• Each interface on a host must be assigned an IP
  address and a subnet mask
• Default Subnet Masks
• Class A - 255.0.0.0
• Class B - 255.255.0.0
• Class C - 255.255.255.0
• A node with multiple interfaces (multiple NICs)
  is called a multihommed host and must have an
  address and subnet mask for each interface

11
IPCONFIG and WINIPCFG

• IPCONFIG is used to show the IP configuration and
  current connections on an Windows NT Windows 2000
  or Windows ME host
• IPCONFIG /ALL
• WINIPCFG is a graphical utility you can use to
  view your IP address in Windows 95/98/ME

12
Dynamic Host Configuration Protocol (DHCP)

• DHCP is a protocol for dynamically assigning IP
  addresses and other configuration parameters to
  hosts
• This eliminates many of the problems associated
  with IP configuration
• Especially useful in complex networks or networks
  in which users are mobile

13
DHCP

• Hosts must be configured to use DHCP
• When the host needs an IP address it requests one
  from the DHCP server
• This packet is sent as a broadcast
• IP parameters and length of address reservation
  period are configured on the server
• DHCP server can provide IP address, subnet mask,
  Default gateway, DNS server, as well as many
  other parameters

14
IPv6

• 128 bits 3.4 x 1038 addresses
• Integrated support for secure communications
• Supports Quality of Service (QoS) features so
  that different types of traffic can be
  prioritized
• Supports host autoconfiguration

15
IPv6

• TLA - Top Level Aggregator ID
• NLA - Next Level Aggregator ID
• SLA - Site Level Aggregator ID
• Interface ID - Host ID

001 TLA reserved NLA SLA
Interface ID 13 bits 8 bits
24 bits 16 bits 64 bits