1. Networking SPARCS 2000 wheel seminar netj@sparcs.kaist.ac.kr

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

3. 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

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

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

6. 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

7. 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

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

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

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

11. DNS Architecture IP  Domain Name –Reversed query –143.248.234.102  102.234.248.143.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.

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

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