Networking in Linux: a brief overview

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Networking in Linuxa brief overview
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TCP/IP

• TCP/IP concepts we have seen are applicable to
  Linux (a version of UNIX, where TCP/IP started)
• Some special IP addresses
• localhost 127.0.0.1 (loopback address)
• Internal networks
• Class A 10.0.0.0
• Class B 172.16.0.0 to 172.31.0.0
• Class C 192.168.0.0 to 192.168.255.0
• Machines behind a firewall can use these internal
  IP numbers to communicate among them.
• Only the firewall machine/device (host) needs to
  have an IP address valid in the Internet.

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Basic configuration files

• You can manually create, change and view the
  basic configuration files
• /etc/hostname
• /etc/hosts
• /etc/resolv.conf
• /etc/interfaces
• See this example for their format. Also a howto.
• Of course you can also do it in an Ubuntu GUI at
  System, Administration, Network.
• defining the interface type (static, IP,
  subnetmask and gateway) or DHCP .
• setting the DNS server.

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Servers and daemons

• Setting up telnet and ftp servers is not
  recommended, use ssh (default in Linux).
• Setting up a Web server (Apache)
• Setting up and configuring SAMBA
• Setting up a firewall
• NIS and NFS
• DHCP
• DNS (bind)
• Xinetd - the super daemon
• Ubuntu documentation.
• A free network admin manual