Networking SPARCS 2000 wheel seminar

TCP/IP Low-level networking software most commonly used with UNIX Internet Protocol Internet Control Message Protocol Address Resolution Protocol User Datagram Protocol

TCP/IP network model Link layer –Network hardware, device drivers Network layer –Basic comm., addressing, routing Transport layer –Comm. Among net programs Application layer –Application programs

Addresses Hardware address IP Address –IP: xxx.xxx.xxx.xxx, 4bytes –Port: TCP/UDP, 2bytes –Internet address classes (A,B,C,D,E)

ARP Address Resolution Protocol Does address translation IP  Hardware Address arp command RARP, BOOTP

Routing Process directing a packet through networks between its source and destination RIP, OSPF, IGRP, EGP, BGP, DVMRP ICMP redirects CIDR (Classless Inter-Domain Routing) route command routed, gated

Network commands ifconfig: configuring network interfaces route: configure static routes ping: check if a host is alive netstat: network status traceroute: trace IP packets tcpdump, etherfind, snoop, arp

DNS Domain Name System Hostnames  IP addresses Distributed database that holds info about computers on the Internet BIND, named

DNS defines, Hierarchical namespace for hosts Host table as a distributed database Library routines for querying Improved routing for Protocol for exchanging naming information

DNS Namespace Top-level domains –COM, EDU, NET, ORG, GOV … Country codes –KR, JP, CA, UK … Root domain. Subdomains –sparcs.kaist.ac.kr,

DNS Architecture IP  Domain Name –Reversed query –  IN-ADDR.ARPA.  sparcs.kaist.ac.kr Domain Name  IP –Querying sparcs.kaist.ac.kr.  kr.  ac.kr.  kaist.ac.kr.  sparcs.kaist.ac.kr.

NFS Network File System Share file systems among computers over network mountd: mount responder nfsd: serve files biod: client-side caching automount

NIS Network Information Service Sharing system files rdist: push files expect: pull files yp commands NIS+