Syngress - Eleventh Hour Network+ Exam N10-004 Study Guide (11 ...

More documents

Recommendations

Info

102 CHAPTER 6 TCP/IP and Routing ■ it must pass through). Any route which is more than 15 hops away is considered unreachable. More appropriate for small- to medium-sized networks. ■ Open shortest path first (OSPF) is a link state routing protocol. Uses a method of dynamically updating routing information through link state advertisements (LSAs) that have information containing both the connected networks and their costs. The cost of each router interface is determined by the administrator to use best connections first. Appropriate for large networks. ■ Interior gateway routing protocol (IGRP) is Cisco proprietary. ■ Enhanced interior gateway routing protocol (EIGRP) is a Cisco proprietary hybrid protocol that combines the nest of advertisements in link-state protocols and the simplicity of distance vector. Exterior gateway protocols (EGP) are designed to control routing between autonomous systems. The three most commonly used IP-based EGP routing protocols are as follows: ■ Border gateway protocol (BGP) is a distance vector routing protocol, and it determines routes based on the number of hops (how many routers it must pass through). ■ Intermediate system–intermediate system (IS–IS) is a link state routing protocol. It uses a method of dynamically updating routing information through LSAs that have information containing both the connected networks and their costs. The cost of each router interface is determined by the administrator to use best connections first. ROUTING UTILITIES Four commonly used routing utilities are as follows: ■ ■ ■ ■ Route is used to view and modify the entries in the routing table. Ping is used to verify connectivity of intended destinations using Internet Control Message Protocol (ICMP) Echo messages. Tracert is used to send ICMP Echo messages to discover the path between a node and a destination. Pathping is used to discover the path between a host and destination or to identify high-loss links. NETWORK ADDRESS TRANSLATION NAT permits an organization’s IP address structure to appear differently to outside networks than the actual address space it is using. It enables private IP networks that use nonregistered RFC1918 IP addresses to connect to the Internet. Characteristics of NAT are as follows: ■ NAT allows hosts on a private network (inside network) to transparently communicate with destination hosts (outside network) in a global or public network by modifying the source address portion of an IP packet as it traverses the NAT device.
Understanding Basic IP Routing 103 ■ ■ ■ ■ ■ ■ The NAT device tracks each translation (conversation) between the source host (inside network) and the destination host (outside network), and vice versa and stores them in internal tables. Some router vendors call NAT tables as translation tables. Cisco calls them xlate on their PIX firewalls. NAT converts IP addresses from the private address space to the public address space. NAT is a method by which IP addresses are mapped from one address realm to another. This translation provides transparent routing from host to host. Port address translation (PAT) translates transport identifiers like TCP and UDP port numbers and ICMP query identifiers. Summary of <strong>Exam</strong> Objectives TCP/IP is a suite of protocols that provides the functionality specified in the OSI model using the four related layers of the Department of Defense model: network interface, Internet, host-to-host, and application. IP addresses are 32-bit addresses represented in dotted decimal format (w.x.y.z). The 32 bits contain both a network and host ID. When sending data, the IP address in the packet is compared, using bitwise ANDing, to the subnet mask. The packet is sent to the appropriate internal or external location depending on the results of the ANDing process. Network addresses were originally designed in a class-based system. Class A with an address range of 1.x.y.z to 126.x.y.z, Class B with an address range of 128.0.y.z to 191.255.y.z, and Class C with an address range of 192.0.0.z to 223.255.255.z. The default subnet masks are: Class A: 255.0.0.0; Class B: 255.255.0.0; and Class C: 255.255.255.0. Classful networks can be subdivided into subnets using custom subnet masks. There is an inverse relationship between the number of subnets and the number of hosts per subnet. Packets destined for networks that are not local are forwarded using gateways or routers. IP routing involves resolving the hostname or NetBIOS name to an IP address and resolving the IP address to a MAC address. NetBIOS name resolution uses four different node types to resolve names to IP addresses: broadcast (B-node), peer-to-peer (P-node), mixed (M-node), and hybrid (H-node). Names can also be resolved by using a HOSTS file or through the DNS or in the case of NetBIOS names with an LMHOSTS file or through WINS. The ARP is used to resolve the IP address to the MAC address that is unique to each Network Interface Card (NIC) manufactured. Routing on a network can be static or dynamic. Four commonly used routing utilities are route, ping, tracert, and pathping. Protocols such as APIPA and DHCP help to get systems logically addressed dynamically. In this chapter, we
Page 2 and 3:
Syngress is an imprint of Elsevier
Page 4 and 5:
xii About the Authors Technical Edi
Page 6 and 7:
2 CHAPTER 1 Network Fundamentals Ne
Page 8 and 9:
4 CHAPTER 1 Network Fundamentals re
Page 10 and 11:
6 CHAPTER 1 Network Fundamentals
Page 12 and 13:
8 CHAPTER 1 Network Fundamentals Wh
Page 14 and 15:
10 CHAPTER 1 Network Fundamentals d
Page 16 and 17:
12 CHAPTER 1 Network Fundamentals
Page 18 and 19:
14 CHAPTER 1 Network Fundamentals T
Page 20 and 21:
16 CHAPTER 1 Network Fundamentals T
Page 22 and 23:
18 CHAPTER 1 Network Fundamentals I
Page 24 and 25:
20 CHAPTER 2 Network Media DID YOU
Page 26 and 27:
22 CHAPTER 2 Network Media Table 2.
Page 28 and 29:
24 CHAPTER 2 Network Media ■ Perf
Page 30 and 31:
26 CHAPTER 2 Network Media Table 2.
Page 32 and 33:
28 CHAPTER 2 Network Media LAN TECH
Page 34 and 35:
30 CHAPTER 2 Network Media CONNECTO
Page 36 and 37:
32 CHAPTER 2 Network Media EXAM WAR
Page 38 and 39:
34 CHAPTER 2 Network Media problems
Page 40 and 41:
36 CHAPTER 2 Network Media electrom
Page 42 and 43:
38 CHAPTER 3 Network Devices Table
Page 44 and 45:
40 CHAPTER 3 Network Devices some o
Page 46 and 47:
42 CHAPTER 3 Network Devices ■
Page 48 and 49:
44 CHAPTER 3 Network Devices ■
Page 50 and 51:
46 CHAPTER 3 Network Devices EXAM W
Page 52 and 53:
48 CHAPTER 3 Network Devices ■ Du
Page 54 and 55:
50 CHAPTER 3 Network Devices Proxy
Page 56 and 57: 52 CHAPTER 3 Network Devices Top Fi
Page 58 and 59: 54 CHAPTER 3 Network Devices the co
Page 60 and 61: 56 CHAPTER 4 Wireless Networking
Page 64 and 65: 60 CHAPTER 4 Wireless Networking Ta
Page 66 and 67: 62 CHAPTER 4 Wireless Networking WE
Page 68 and 69: 64 CHAPTER 4 Wireless Networking Th
Page 70 and 71: 66 CHAPTER 4 Wireless Networking us
Page 74 and 75: 70 CHAPTER 4 Wireless Networking si
Page 76 and 77: 72 CHAPTER 4 Wireless Networking co
Page 78 and 79: 74 CHAPTER 5 The OSI Model and Netw
Page 94 and 95: 90 CHAPTER 6 TCP/IP and Routing ■
Page 96 and 97: 92 CHAPTER 6 TCP/IP and Routing For
Page 98 and 99: 94 CHAPTER 6 TCP/IP and Routing UND
Page 100 and 101: 96 CHAPTER 6 TCP/IP and Routing ■
Page 102 and 103: 98 CHAPTER 6 TCP/IP and Routing Sub
Page 104 and 105: 100 CHAPTER 6 TCP/IP and Routing co
Page 108 and 109: 104 CHAPTER 6 TCP/IP and Routing al
Page 110 and 111: CHAPTER 7 Wide Area Networking 107
Page 112 and 113: WAN Protocols and Properties 109 In
Page 114 and 115: WAN Protocols and Properties 111 Cr
Page 116 and 117: Internet Access Methods 113 EXAM WA
Page 118 and 119: Internet Access Methods 115 Wireles
Page 120 and 121: Internet Access Methods 117 Top Fiv
Page 122 and 123: Internet Access Methods 119 with th
Page 124 and 125: 122 CHAPTER 8 Security Standards an
Page 146 and 147: 144 CHAPTER 9 Network Management
Page 148 and 149: 146 CHAPTER 9 Network Management Wi
Page 150 and 151: 148 CHAPTER 9 Network Management Cr
Page 152 and 153: 150 CHAPTER 9 Network Management
Page 154 and 155: 152 CHAPTER 9 Network Management An
Page 156 and 157:
154 CHAPTER 9 Network Management Lo
Page 158 and 159:
156 CHAPTER 10 Network Troubleshoot
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Glossary 177 Access Determines who
Page 180 and 181:
Glossary 179 Extensible Authenticat
Page 182 and 183:
Glossary 181 Oscilloscope A cable t
Page 184 and 185:
Glossary 183 Wireless Network A net
Page 186 and 187:
186 Index Data link layer, 74-75 fu
Page 188 and 189:
188 Index Network troubleshooting,
show all

Syngress - Eleventh Hour Network+ Exam N10-004 Study Guide (11 ...

Create successful ePaper yourself

Delete template?

Save as template?