Network Tools and Terms

Networking Tools

arp		Address resolution protocol Type "arp -a" to display entries in the arp cache.
ifconfig		A command line tool used to configure a network interface. There is a man page available for this program.
ifdown		Shuts down a network interface
ifup		Starts a network interface such as eth0 or ppp0
ipchains		A tool used to administer firewall rules.
netconf		The Redhat GUI network configuration tool.
netconfig		Another network configuration tool which is usually run when the system is installed. Netconf is better.
netstat		Type "netstat -rn" to see the routing table. Type "netstat-in" to see the interface info.
nslookup		Used to test DNS configuration by querying DNS servers.
ping		A network tool used to sent ICMP test packets to other hosts to determine if they can respond or are reachable.
ripquery		A tool to query some routers for their routing table.
route		Typing "route -n" will show the routing table
tcpdump		A network sniffer tool used to dump headers of packets on a network interface.
traceroute		Sends data to a remote host to a port that doesn't exist with a TTL field at 1,2,etc to get the intermediate hosts to send back their addresses reporting errors. The destination will report an unreachable port error sending its address.

Networking terms

• ARP - Address resolution protocol. Used to translate hardware addresses (ethernet ports) and IP addresses and vice versa. Uses broadcast messages for resolution.
• BOOTP - A protocol used to allow client computers to get their IP address from a BOOTP server. DHCP supercedes, though does not replace this protocol.
• DHCP - Dynamic Host Configuration Protocol, allows clients to get their IP addresses from a DHCP server. This system "leases" IP addresses to clients for limited periods of time. If the client has not used their IP address within the lease time, the IP address is free fro re-assignment.
• ICMP - Internet Control Message Protocol. Part of the IP layer. Communicates error messages and other messages that require attention.
• IGMP - Internet Group Management Protocol. Protocol used to manage multicasting through routers.
• IP - Three kinds of IP addresses are unicast, broadcast and multicast.
• MBONE - Used to refer to a network that supports multicasting.
• NIS - Network information service, is a name service created by Sun Microsystems.
• NFS - Network file sharing, allows two Unix style computers to mount and access part or all of a file system on a remote computer.
• OSPF - Open Shortest Path First dynamic routing protocol intended as a replacement for RIP.
• PPP - Point to point protocol is a serial protocol commonly used to connect using a modem to the internet
• RARP - Reverse ARP, used for clients to determine their IP addresses.
• RIP - Routing Information Protocol, used by almost all TCP/IP implementation to perform dynamic routing.
• RPC - Remote procedure call is a set of function calls used by a client program to call functions in a remote server program.
• SLIP - Serial line internet protocol
• SMTP - Simple mail transport protocol, commonly uset as the mail message transport protocol.
• SNMP - Simple network management protocol.
• UDP - User Datagram Protocol, a transport layer protocol
• UUCP - Unix to Unix copy is a protocol that allows Unix computers to exchange files.