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;Advance Praise for Head First Networking;Praise for other Head First books;Authors of Head First Networking;How to Use this Book: Intro; Who is this book for?; We know what you''re thinking; We know what your brain is thinking; Metacognition: thinking about thinking; Here''s what WE did:; Here''s what YOU can do to bend your brain into submission; Read Me; The technical review team; Acknowledgments; Safari® Books Online;
Chapter 1: Fixing Physical Networks: Walking on Wires;
1.1 Coconut Airways has a network problem;
1.2 How do we fix the cable?;
1.3 Introducing the CAT-5 cable;
1.4 The CAT-5 cable dissected;
1.5 So what''s with all the colors?;
1.6 Let''s fix the broken CAT-5 cable;
1.7 A closer look at the RJ-45 connector;
1.8 So what are the physical steps?;
1.9 You fixed the CAT-5 cable;
1.10 Coconut Airways has more than one network;
1.11 Introducing the coaxial cable;
1.12 Coaxial networks are bus networks;
1.13 So can we fix the cable?;
1.14 The network''s still not working;
1.15 So what goes on inside a coaxial cable?;
1.16 What about connectors and terminators?;
1.17 Use toner-tracer sets to listen to electrons;
1.18 No sound means no electrons;
1.19 You''ve fixed the coaxial cable;
1.20 Introducing fiber-optic cables;
1.21 The Coconut Airways cable''s over-bent;
1.22 How to fix fiber-optics with a fusion splicer;
1.23 A fiber-optic connector needs fitting too;
1.24 We''re nearly ready to fix the connector;
1.25 There are two types of fiber;
1.26 Which mode fiber should you use?;
1.27 Let''s fit the connector on the fiber-optic;
1.28 Coconut Airways is sky high;
Chapter 2: Planning Network Layouts: Networking in the Dark;
2.1 Ghost Watch needs your help!;
2.2 Every good network needs a good plan;
2.3 So how does the device list help us plan a network?;
2.4 How to plan a network layout;
2.5 Let''s plan the cabling with a floorplan;
2.6 Ready to plot some network cables?;
2.7 So where have we got to?;
2.8 We need to decide on the cable management hardware;
2.9 Uh oh! The cabling is a mess;
2.10 Ghost Watch needs cable management hardware;
2.11 Things that go bump...;
2.12 You''ve really cleaned up that noise and straightened out MOST of the cables!;
2.13 Let''s start by labeling the cables;
2.14 But there are still lots of cables;
2.15 So what''s a patch panel?;
2.16 Behind the scenes of a patch panel;
2.17 The wires go into a punch down block;
2.18 Roll the cameras!;
Chapter 3: Tools and Troubleshooting: Into the Wire;
3.1 Mighty Gumball won the Super Bowl contract;
3.2 A toner and tracer can check for a signal...;
3.3
... but can''t check for signal quality;
3.4 Introducing the multimeter;
3.5 So what''s resistance?;
3.6 So how well did the multimeter do?;
3.7 An oscilloscope shows voltage changes;
3.8 Voltage is really electrical pressure;
3.9 Where does noise on network cables come from?;
3.10 So how well did the oscilloscope perform for Mighty Gumball?;
3.11 A logical analyzer uses voltage too;
3.12 When is a logical analyzer useful?;
3.13 So which tool is best?;
3.14 The Mighty Gumball bonus went to Jill;
3.15 A LAN analyzer combines the functions of all the other tools;
3.16 A LAN analyzer understands the network traffic in the signal;
3.17 So which tool is best?;
3.18 The Mighty Gumball problems are fixed!;
Chapter 4: Packet Analysis: You''ve Been Framed;
4.1 What''s the secret message?;
4.2 Network cards handle encoding;
4.3 To get the message, reverse the encoding;
4.4 The Ethernet standard tells hardware how to encode the data;
4.5 A quick guide to binary;
4.6 Computers read numbers, humans read letters;
4.7 Hexadecimal to the rescue;
4.8 We can convert to ASCII using hex;
4.9 Back at the spy agency...;
4.10 Protocols define the structure of a message;
4.11 Network frames have lots of layers;
4.12 Your friendly packet field guide;
4.13 So can we decode the secret message?;
4.14 We''ve got all the right packets... but not necessarily in the right order;
4.15 The packet tells you the correct order;
Chapter 5: Network Devices and Traffic: How Smart is Your Network?;
5.1 You''ve decoded the secret message...;
5.2 The packet information tells us where the packet came from;
5.3 So who''s the mole?;
5.4 There''s more to networks than computers;
5.5 Hubs don''t change the MAC address;
5.6 A hub sends signals, and sends them everywhere;
5.7 So what passed the signal to the hub?;
5.8 A switch sends frames, and only sends them where they need to go;
5.9 Switches store MAC addresses in a lookup table to keep the frames flowing smoothly;
5.10 The switch has the information...;
5.11 We can use software to monitor packets;
5.12 Let''s hook Wireshark up to the switch;
5.13 Wireshark gives us traffic information;
5.14 Routers have MAC addresses too;
5.15 We''re closing in!;
5.16 You''ve found the mole!;
Chapter 6: Connecting Networks with Routers: Bringing Things Together;
6.1 Networking Walking on the moon;
6.2 We need to connect two networks together;
6.3 The light''s on, but nobody''s home;
6.4 Let''s see what traffic is on our network!;
6.5 MAC address versus IP address;
6.6 IP addresses give our networks a sense of location, and network nodes a sense of belonging to that location;
6.7 We retrieve IP addresses using the MAC address and the Address Resolution Protocol (ARP);
6.8 So what''s the problem with the Moonbase?;
6.9 How do we get network traffic to move between networks?;
6.10 How the router moves data across networks;
6.11 Back to the Moonbase problem;
6.12 The secret of IP numbers is...;
6.13 Routers connect networks by doing the math...;
6.14 Back at the Moonbase...;
6.15 Are you ready to program the router?;
6.16 You just created this router config file!;
6.17 Let the router tell us what''s wrong...;
Chapter 7: Routing Protocols: It''s a Matter of Protocol;
7.1 Houston, we have a problem...;
7.2 Routing tables tell routers where to send packets;
7.3 Each line represents a different route;
7.4 So how do we enter routes?;
7.5 Routes help routers figure out where to send network traffic;
7.6 So are the moonbases now connected?;
7.7 Back on the moon...;
7.8 So how do we troubleshoot bad routes?;
7.9 The traceroute command is useful too;
7.10 So what''s the problem with the network connection?;
7.11 The network address changes keep on coming...;
7.12 Use RIP to get routes to update themselves;
7.13 So how do we set up RIP?;
7.14 But there''s still a problem...;
7.15 There are too many hops;
7.16 The routing protocol zoo;
7.17 So how do we setup EIGRP?;
7.18 We have lift off!;
Chapter 8: The Domain Name System: Names to Numbers;
8.1 The Head First Health Club needs a website;
8.2 Hello, my domain name is...;
8.3 Let''s go buy a domain name;
8.4 Uh-oh! We''re in trouble;
8.5 Introducing the DNS;
8.6 The DNS relies on name servers;
8.7 How the DNS sees your domain;
8.8 So how does this affect the Health Club?;
8.9 First install a DNS name server...;
8.10
...then configure the name server;
8.11 The anatomy of a DNS zone file;
8.12 Here''s what the DNS zone file tells us about the Health Club servers;
8.13 The Health Club can''t send emails;
8.14 So what''s the problem?;
8.15 Email servers use RDNS to fight SPAM;
8.16 Check your sources with reverse DNS;
8.17 The dig command can do a reverse DNS lookup;
8.18 Your name server has another important zone file...;
8.19 The emails are working!;
Chapter 9: Monitoring and Troubleshooting: Listen to Your Network''s Troubles;
9.1 Pajama Death are back on tour;
9.2 So where would you start troubleshooting a misfiring network?;
9.3 Start troubleshooting your network problems by checking in with your network devices;
9.4 Troubleshoot network connectivity with the ping command;
9.5 If the ping fails, check the cables;
9.6 Get started with the show interface command;
9.7 The ticket network''s still not fixed;
9.8 SNMP to the rescue!;
9.9 SNMP is a network admininistrator''s communication tool;
9.10 How to configure SNMP on a Cisco device;
9.11 One hour to go...;
9.12 Get devices to send you their problems;
9.13 How to configure syslogd on a Cisco device;
9.14 How do you tell what''s in the logs?;
9.15 Too much information can be just as bad as not enough;
9.16 How do you know which events are important?;
9.17 Pajama Death''s a sell-out!;
Chapter 10: Wireless Networking: Working Without Wires;
10.1 Your new gig at Starbuzz Coffee;
10.2 Wireless access points create networks using radio waves;
10.3 Let''s fit the wireless access point;
10.4 What about the network configuration?;
10.5 So what''s DHCP?;
10.6 First make sure the client has DHCP turned on...;
10.7 Second, make the wireless access point a DHCP server...;
10.8
...and then specify an acceptable range of IP addresses;
10.9 So has setting up DHCP solved the problem?;
10.10 This time it''s personal;
10.11 We''ve run out of IP addresses;
10.12 NAT works by reallocating IP addresses;
10.13 So how do we configure NAT?;
10.14 So has this fixed the problem?;
10.15 There''s more than one wireless protocol;
10.16 The central Starbuzz server needs to access the cash register;
10.17 Port mapping to the rescue!;
10.18 Let''s set up port mapping on the Starbuzz access point;
10.19 The wireless access point is a success!;
Chapter 11: Network Security: Get Defensive;
11.1 The bad guys are everywhere;
11.2 And it''s not just the NETWORK that gets hurt...;
11.3 The big four in network security;
11.4 Defend your network against MAC address spoofing;
11.5 So how do we defend against MAC address spoofing?;
11.6 Defend your network against ARP poisoning attacks;
11.7 So what can we do about ARP poisoning attacks?;
11.8 It''s all about the access, baby!;
11.9 Set up your router''s Access Control Lists to keep attackers out;
11.10 So how do we configure the Access Control List?;
11.11 Firewalls filter packets between networks;
11.12 Packet-filtering rules!;
11.13 Master the static packet filter;
11.14 Get smart with stateful packet-filters;
11.15 Humans are the weakest link in your security chain;
11.16 So how do social engineers operate?;