1. Linux Networking #1 Dr. Michael L. Collard www.sdml.info/collard www.sdml.info/collard/linux collard@cs.kent.edu 1

2. TCP/IP Set of protocols for computer communication IP (Internet Protocol) – get packets from one machine to another, best effort (OSI Layer 3) Layer 4 Protocols: – TCP (Transmission Control Protocol) – ordered and guaranteed delivery

3. IP-Based Protocols TCP (Transmission Control Protocol) Connection-oriented, provides ordered and guaranteed delivery to IP, manages ports Applications using TCP: telnet, http servers, ssh, email, etc. UDP (User Datagram Protocol) Adds port addressing to IP, lower overhead, no guarantees Applications using UDP: domain name service (DNS), host configuration (DHCP) ICMP (Internet Control Message Protocol) diagnostic and traffic control messages Applications using ICMP: ping, traceroute

4. Networking Setup /etc/services – standard ports and services /etc/init.d/network – start, stop, restart, reload, status /etc/rc.d – runlevel network startup and shutdown ifconfig - configure a network interface ifup – bring a network interface up ifdown – bring a network interface down

5. Networking Tools #2 iwconfig, iwlist – wireless setup and information netstat – network current status ping – IP communication status traceroute – route packets take to a given host tcpdump – monitor packets