* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 2.2 Internet Protocol
Survey
Document related concepts
Dynamic Host Configuration Protocol wikipedia , lookup
Airborne Networking wikipedia , lookup
Net neutrality wikipedia , lookup
Distributed firewall wikipedia , lookup
Deep packet inspection wikipedia , lookup
Wake-on-LAN wikipedia , lookup
Net neutrality law wikipedia , lookup
Computer network wikipedia , lookup
Internet protocol suite wikipedia , lookup
Piggybacking (Internet access) wikipedia , lookup
List of wireless community networks by region wikipedia , lookup
Cracking of wireless networks wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Transcript
CompTIA Server+ Certification (Exam SK0-004) 2.2 Internet Protocol This courseware is copyrighted © 2016 gtslearning. No part of this courseware or any training material supplied by gtslearning International Limited to accompany the courseware may be copied, photocopied, reproduced, or re-used in any form or by any means without permission in writing from a director of gtslearning International Limited. Violation of these laws will lead to prosecution. All trademarks, service marks, products, or services are trademarks or registered trademarks of their respective holders and are acknowledged by the publisher. All gtslearning products are supplied on the basis of a single copy of a course per student. Additional resources that may be made available from gtslearning may only be used in conjunction with courses sold by gtslearning. No material changes to these resources are permitted without express written permission by a director of gtslearning. These resources may not be used in conjunction with content from any other supplier. If you suspect that this course has been copied or distributed illegally, please telephone or email gtslearning. Objectives • Describe the properties and characteristics of Internet Protocol (IP) addressing • Configure appropriate settings for an IP host • Troubleshoot IP configuration issues using command-line tools 2.2 Internet Protocol 100 The TCP/IP Suite • IP (Internet Protocol) • ARP (Address Resolution Protocol) • ICMP (Internet Control Message Protocol) • TCP (Transmission Control Protocol) • UDP (User Datagram Protocol) • Application protocols 2.2 Internet Protocol 100 IPv4 Address Format • IP address represents o The network number (network ID) - this number is common to all hosts on the same network o The host number (host ID) - this unique number identifies a host on a particular network • 32-bit binary value o 11000110001010010001000000001001 • Expressed in 8-bit octets o 11000110 00101001 00010000 00001001 • Converted to dotted decimal notation for entry into configuration dialogs o 198.41.16.9 2.2 Internet Protocol 101 Binary / Decimal Conversion • Number bases o Place value o Base 10 (Decimal) o Base 2 (Binary) • Converting between binary and decimal 128 64 32 16 8 4 2 1 1 1 1 0 1 1 0 1 128 x 1 64 x 1 32 x 1 16 x 0 8 x 1 4 x 1 2 x 0 1 x 1 128 64 32 16 8 4 2 1 128 x 1 64 x 1 32 x 0 16 x 0 8 x 0 4 x 1 2 x 1 1 x 1 1 1 0 0 0 1 1 1 2.2 Internet Protocol 102 Subnet Masks • IP address represents both a network ID and host ID • A mask is applied to identify the network and host portions • A “1” in the mask means corresponding bit in the address is part of the network ID • “1”s in mask must be contiguous o 11111111 11110000 00000000 00000000 – VALID o 11111111 00000000 11110000 00000000 - INVALID 2.2 Internet Protocol 102 Masking an IP Address (ANDing) • To work out a network ID, given an address and mask in decimal, convert to binary and back IP address (172.30.15.12) 10101100 00011110 00001111 00001100 Mask (255.255.0.0) Network ID (172.30.0.0) 11111111 11111111 00000000 00000000 2.2 Internet Protocol 10101100 00011110 00000000 00000000 103 Routing Decision • Local network Source IP (172.30.15.12) 10101100 00011110 00001111 00001100 Mask (255.255.0.0) 11111111 11111111 00000000 00000000 Destination IP (172.30.16.101) 10101100 00011110 00010000 01100101 • Remote network Source IP (172.30.15.12) 10101100 Mask (255.255.0.0) 11111111 Destination IP (172.31.16.101) 10101100 2.2 Internet Protocol 00011110 11111111 00011111 00001111 00000000 00010000 00001100 00000000 01100101 103 IP Class 2.2 Internet Protocol 104 Configuring IP • IP Address o Enter using dotted decimal notation • Subnet Mask o Usually specified in dotted decimal • Default Gateway o IP address of the router handling transmissions to remote networks • Client-side DNS (Domain Name System) o IP address(es) of DNS servers handling name resolution • Client-side WINS (Windows Internet Name Service) 2.2 Internet Protocol 105 DHCP and APIPA • Dynamic Host Configuration Protocol o Reduces chance of configuration errors and simplifies administration o Configure IP settings on a central server o Client contacts server to obtain configuration o IP addresses leased from a pool o Critical network infrastructure usually uses static addressing however (to reduce risks from DHCP service failure / compromise) • Automatic IP Addressing (APIPA) 2.2 Internet Protocol o Host that is configured to contact a DHCP server might not be able to o Defaults to using an address from the APIPA range o Can communicate with other APIPA hosts on the local network 107 Public and Private Addressing • Address ranges not routable over the Internet o 10.0.0.0 to 10.255.255.255 o 172.16.0.0 to 172.31.255.255 o 192.168.0.0 to 192.168.255.255 o 169.254.0.0 to 169.254.255.255 − Used by hosts for link-local autoconfiguration / Automatic Private IP Addressing (APIPA) • Hosts on the private network must use some mechanism to access the Internet o Network Address Translation (NAT) o Proxy 2.2 Internet Protocol 108 Classless Addressing • Classful addressing not sustainable • Classless Interdomain Routing (CIDR) o o o Netmask does not have to align on an octet boundary Routing decisions made on basis of network prefix, representing number of bits in mask (e.g. /21) Some configuration dialogs might require CIDR notation rather than dotted decimal mask (e.g. firewall rule configuration) 2.2 Internet Protocol 109 Planning an IPv4 Addressing Scheme (1) • Consider o Whether you need a public or private addressing scheme o How many networks you need o How many subnetworks you need o How many hosts per subnet • Addressing Rules o Network ID cannot be 127 o Network and / or host IDs cannot be all 255 (all 1s in binary) o Network and / or host ID cannot be 0 (all zeros in binary) o Host ID must be unique in the subnet o Network ID must be unique − On the Internet (if using a public addressing scheme) − On your internal system of networks (if using a private addressing scheme) 2.2 Internet Protocol 110 Planning an IPv4 Addressing Scheme (2) • Work out how many subnets are needed o Must be a power of 2 o Exponent (the value of “n” in 2n) is the number of bits to add to the default network prefix • Check that subnets allow for sufficient hosts (2n-2 where “n” is number of host bits) • Work out the subnets - deduct the least significant octet in the mask from 256 • Work out the next subnet ID - the lowest subnet value higher • Work out the host ranges for each subnet o Take the subnet address and add a binary 1 to it for the first host o Take the next subnet ID and deduct two binary digits from it 2.2 Internet Protocol 111 ipconfig • Windows utility reporting IP configuration o ipconfig /all o ipconfig /release AdapterName o ipconfig /renew AdapterName o ipconfig /displaydns o ipconfig /flushdns • Identify static configuration • Look for APIPA address / limited connectivity icon 2.2 Internet Protocol 112 ifconfig • Linux utility for reporting and modifying IP configuration o o o 2.2 Internet Protocol Can be used to change configuration (though changes lost at next boot) and bring adapter up or down Does not support DHCP or DNS switches Does not show default gateway (use route) 113 ping • ping IPAddress • ping HostName • Internet Control Message Protocol (ICMP) • Standard tests o Ping the loopback address (ping 127.0.0.1) o Ping the host’s IP address o Ping the IP address of the default gateway o Ping the IP address of a remote host 2.2 Internet Protocol 114 Interpreting ping Output • Reply from, round trip time and packet loss o Detect whether a link is slow or experiences packet loss o Use tracert to identify where on the route there is a problem • Destination unreachable o No route to host o Check IP configuration o Check router (default gateway) • No reply / timed out 2.2 Internet Protocol o Host / interface is down o Host cannot route reply o Firewall 114 Troubleshooting Connectivity Issues • Verify configuration (ipconfig / ifconfig) • Check DHCP • Test connectivity with ping o Loopback o Workstation address o Default gateway (or other local host) 2.2 Internet Protocol 115 IP Version 6 • IPv4 address shortage o 32-bit address space o Inefficiently allocated o Complex routing tables • IPv6 / IPng o 128-bit address space o Cope with mobile / “Internet of Things” growth o Hierarchical address allocation (simpler routing) • Very slow transition! 2.2 Internet Protocol 116 Hexadecimal Numbering • Base 10 (decimal) - 0-9 and place value powers of 10 • Base 2 (binary) - 0 or 1 and place value powers of 2 • Base 16 (hex) - up to 16 values represented by 0-9 and A, B, C, D, E, F o 1 hex digit can represent 4 binary digits (a “nibble”) o 2 hex digits can represent 1 octet (byte / 8 bits) o 4 hex digits can represent 1 double-byte (16 bits) 2.2 Internet Protocol 116 IPv6 Address Notation • 128-bit binary address = lots of typing! o 0010 0000 0000 0001 0000 1101 1011 1000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1010 1011 1100 0000 0000 0000 0000 1101 1110 1111 0000 0001 0010 0011 0100 • Hex notation o Each hex digit represents 4 binary digits o Hex digits are arranged in 8 x 16-bit (double byte) blocks separated by colons − 2001:0db8:0000:0000:0abc:0000:def0:1234 • Zero compression o Can omit leading zeroes o Can compress one sequence of “all zero” double bytes − 2001:db8::abc:0:def0:1234 2.2 Internet Protocol 117 IPv6 Addressing Schemes • In IPv6, host bits are fixed o Network prefix (64-bit) o Host ID (64-bit) • Global o 001 binary prefix (2 or 3 in hex) o Next 45 bits allocated to registries and ISPs o Following 16 bits for subnetting o 64 bits for interface − MAC-derived / EUI-64 − Pseudo-random token • Link-local o 1111111010 binary prefix (or fe80 in hex) o Not routable o Communicate with same subnet (neighbors) o All interfaces have link-local addresses 2.2 Internet Protocol 117 IPv4 versus IPv6 Misconfiguration • Incorrect address or network prefix • Networks running both IPv4 and IPv6 o o Which protocol is in use for a given connection Whether IPv4 or IPv6 are enable or disabled on particular hosts? 2.2 Internet Protocol 118 Review • Describe the properties and characteristics of Internet Protocol (IP) addressing • Configure appropriate settings for an IP host • Troubleshoot IP configuration issues using command-line tools 2.2 Internet Protocol 119 Labs • Lab 4 / Configuring Network Settings 2.2 Internet Protocol