1. Fall 2011 Nassau Community College ITE153 – Operating Systems 1 Session 9 Networking & Operating Systems (part 2)

2. IPv6, OSI, Standards Fall 2011 Nassau Community College ITE153 – Operating Systems 2 Networking & Operating Systems

3. IPv6 ●1995 – RFC 1752 IPng ●1998 – RFC 2460 IPv6 ●Functional enhancements for a mix of data streams (graphic and video) ●Driving force was address depletion 128-bit addresses ●Started in Solaris 2.8, Windows 2000 Fall 2011 Nassau Community College ITE153 – Operating Systems 3

4. IPv6 Packet w/Extension Headers Fall 2011 Nassau Community College ITE153 – Operating Systems 4

5. OSI Layers Fall 2011 Nassau Community College ITE153 – Operating Systems 5

6. OSI Environment Fall 2011 Nassau Community College ITE153 – Operating Systems 6

7. Internet Standards and RFCs ●Internet Architecture Board (IAB) - overall architecture ●Internet Engineering Task Force (IETF) - engineering and development ●Internet Engineering Steering Group (IESG) - manages the IETF and standards process Fall 2011 Nassau Community College ITE153 – Operating Systems 7

8. Request For Comments (RFC) ●RFCs are the working notes of the Internet research and development community Fall 2011 Nassau Community College ITE153 – Operating Systems 8

9. Standardization Process ●Stable and well understood ●Technically competent ●Substantial operational experience ●Significant public support ●Useful in some or all parts of Internet Fall 2011 Nassau Community College ITE153 – Operating Systems 9 Key difference from ISO: operational experience

10. RFC Publication Process Fall 2011 Nassau Community College ITE153 – Operating Systems 10

11. Hands-on Exercises Fall 2011 Nassau Community College ITE153 – Operating Systems 11

12. What Is My IPAddress? ●You can find it for your interface using any one of the commands: ifconfig ifconfig –a ifconfig [interface] netstat -i Fall 2011 Nassau Community College ITE153 – Operating Systems 12

13. Here’s How I Bring the Interface Up ●Assume my interface is eth0, then use: ifconfig eth0 ● You will get: Fall 2011 Nassau Community College ITE153 – Operating Systems 13 eth0 Link encap:Ethernet HWaddr 00:30:1b:48:dc:3d inet addr:192.168.0.100 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::230:1bff:fe48:dc3d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1494920 errors:0 dropped:0 overruns:0 frame:0 TX packets:1219954 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1621598747 (1.6 GB) TX bytes:302524693 (302.5 MB) Interrupt:17

14. Here’s An Example: ●Assume my interface is eth0, then use: ifconfig eth0 192.168.0.100 netmask 255.255.255.0 broadcast 192.168.0.255 up ●You probably don’t have permission to do this Fall 2011 Nassau Community College ITE153 – Operating Systems 14

15. How Do I Know I Can Get Out On the Network? ●We use the ping command ●It is very simple. It sends an ICMP_ECHO_REQUEST packet to a target host and waits for an answer ●It is one of the workhorses of network debugging ●Here’ an example: ping www.google.eduwww.google.edu ● Some sites disable ping responses! Fall 2011 Nassau Community College ITE153 – Operating Systems 15

16. Ping Sample papacosta@papacosta-desktop:~$ ping www.google.com PING www.l.google.com (74.125.226.208) 56(84) bytes of data. 64 bytes from lga15s28-in-f16.1e100.net (74.125.226.208): icmp_req=1 ttl=55 time=9.82 ms 64 bytes from lga15s28-in-f16.1e100.net (74.125.226.208): icmp_req=2 ttl=55 time=9.86 ms 64 bytes from lga15s28-in-f16.1e100.net (74.125.226.208): icmp_req=3 ttl=55 time=10.7 ms 64 bytes from lga15s28-in-f16.1e100.net (74.125.226.208): icmp_req=4 ttl=55 time=13.6 ms ^C --- www.l.google.com ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3004ms rtt min/avg/max/mdev = 9.821/11.013/13.607/1.545 ms Fall 2011 Nassau Community College ITE153 – Operating Systems 16

17. netstat Command to Check Routing ●The netstat command provides a wealth of information about the state of your computer's networking software, including interface statistics, routing information, and connection tables ●Here are some typical commands to  monitor connection status: netstat -a  see interface status: netstat -i  display routing table: netstat -r –n  View operational stats: netstat -s Fall 2011 Nassau Community College ITE153 – Operating Systems 17

18. nslookup Command ●The nslookup command is a very old command (used in both UNIX and DOS/Windows) to query the DNS database ●Here is an example: nslookup www.google.com Fall 2011 Nassau Community College ITE153 – Operating Systems 18

19. dig Command ●The dig command is in functionality, but has more sensible defaults, provides more info, and has a nicer user interface ●Here are a few examples: dig www.google.com dig google.com any dig google.com mx dig google.com ns dig -x 216.239.34.10www.google.com ●This can get even more involved: dig +nocmd google.com any +multiline +noall +answer Fall 2011 Nassau Community College ITE153 – Operating Systems 19

20. Important URLs ●Internetworking Technology Handbook – Cisco’s excellent and extensive Wiki on networking technologyInternetworking Technology Handbook ●http://www.rfc-editor.org/rfcsearch.html - great place to search RFCshttp://www.rfc-editor.org/rfcsearch.html ●Dig How To Guide - an excellent explanation, with lots of examples, on how to effectively use the dig command line toolDig How To Guide ●Linux: Check Network Connection Command – good explanation of the ss and netstat commandsLinux: Check Network Connection Command ●IP Chicken – this displays your “public” IP addressIP Chicken Fall 2011 Nassau Community College ITE153 – Operating Systems 20

21. Homework Review the Slides Do the Exercise: ipconfig, ping, netstat, nslookup, & dig Complete the Take-Home Exam Fall 2011 Nassau Community College ITE153 – Operating Systems 21