IPv4 Host Address Configuration

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• Each host must be configured with an IP address and subnet mask at a minimum to communicate on an IPv4 network
  • Several other parameters must be configured for a host to make full use of an enterprise network or the Internet
  • also different ways to supply this configuration information to hosts
    • set manually in static configuration:
      • IPv4 address is entered as four decimal numbers separated by periods, such as 192.168.0.100
      • subnet mask is entered in dotted decimal notation, such as 255.255.255.0
        • When used with the IP address 192.168.0.100, the last octet is the host ID
        • could also be entered as the mask length in bits: 24

Info

• host cannot be assigned the first or last address in an IP network
• first address is used to identify the network itself
• last address is used to broadcast to all hosts

• Two other parameters are typically configured to make the host fully functional:
  • default gateway parameter
    • is the IPv4 address of a router
    • is the IP address to which packets destined for a remote network should be sent by default
    • not compulsory, but failure to enter a gateway would limit the host to communication on the local network only
  • One or more Domain Name System (DNS) server IPv4 addresses
    • provide resolution of host and domain names to their IP addresses
    • Most local networks also use DNS for name resolution
    • primary DNS server address would be configured as the same as the gateway address
      • router would be configured to forward DNS queries to a secure resolver
    • two DNS server addresses (preferred and alternate) are specified for redundancy