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

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

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

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

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

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

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

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

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

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

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

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

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: Bcast: Mask: inet6 addr: fe80::230:1bff:fe48:dc3d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets: errors:0 dropped:0 overruns:0 frame:0 TX packets: errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes: (1.6 GB) TX bytes: (302.5 MB) Interrupt:17

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

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 ● Some sites disable ping responses! Fall 2011 Nassau Community College ITE153 – Operating Systems 15

Ping Sample ping PING ( ) 56(84) bytes of data. 64 bytes from lga15s28-in-f16.1e100.net ( ): icmp_req=1 ttl=55 time=9.82 ms 64 bytes from lga15s28-in-f16.1e100.net ( ): icmp_req=2 ttl=55 time=9.86 ms 64 bytes from lga15s28-in-f16.1e100.net ( ): icmp_req=3 ttl=55 time=10.7 ms 64 bytes from lga15s28-in-f16.1e100.net ( ): icmp_req=4 ttl=55 time=13.6 ms ^C ping statistics 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

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

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 Fall 2011 Nassau Community College ITE153 – Operating Systems 18

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 dig google.com any dig google.com mx dig google.com ns dig -x www.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

Important URLs ●Internetworking Technology Handbook – Cisco’s excellent and extensive Wiki on networking technologyInternetworking Technology Handbook ● - great place to search RFCshttp:// ●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

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