1 Objectives Identify the basic components of a network Describe the features of Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6) Configure clients for IPv4 and IPv6 Upgrade a network from IPv4 to IPv6 Troubleshoot Transmission Control Protocol/Internet Protocol on networks

2 Introduction to Networking Basics of networking –A network is a group of two or more nodes –Networking is the practice of: Designing, implementing, and managing a collection of computers and devices or a network

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4 Network topology: Physical and logical relationship among devices

5 Basic Network Components Network interface cards (NICs) Repeater –Receives a signal & resends at a higher level or power Hubs – Have multiple ports to which nodes connect Network bridges –Connect one or more network segments Switches –Work at Layer 2 of the OSI model and forward frames between ports based on MAC addresses. Avoid collision. Routers –Forward packets between subnets, or networks –Connected to at least two networks

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Four-Layer Conceptual Model

8 IPv4 Address IPv4 –Uses unique 32-bit (4-byte) addresses –Each byte is called Octet

9 Subnetting The process of creating multiple smaller networks, or subnets, from an IP network address Subnet mask –Can determine the network and host ID portions of an IP address

IP Address Class Network ID cannot be 127 (loopback) ID bits cannot be all “1”s (broadcast) ID bits cannot be all “0”s. Host ID must be unique. IP address of client gateway is the router.

11 Subnetting (continued) Special-use IPv4 addresses –Mulitcast: to –Reserved: to –Private IP: to to to –Automatic Private IP Address: to –Loopback: 127.x.x.x Classless Interdomain Routing (CIDR) –Uses variable length subnet masks. E.g /13 means first 13 bits are network ID Supernetting –Combine two or more subnetworks into a larger supernetwork

12 Introduction to IPv6 IPv6 Advantages: Improved security  Built-in encryption Improved autoconfiguration by routers Simplified routing  Neighbor Discovery Addressing with IPv6 –IPv6 addresses are 128 bits, or 16 bytes, Expressed in 8 groups of 4 hexadecimal digits, separated by colon : –For UNC path, replace : by – and append.ipv6-literal.net E.g. \\2008--b-2f ab.ipv6.literal.net\ \myShare –For URL, enclose IPv6Address in brackets. E.g. –IPv6 rules for shortening addresses Any leading digit of 0 can be dropped from any group Two or more groups of zeroes can be replaced by two colons (can be done only once per address) –CIDR notation for subnetting an address

13 IPv6 Address Types IPv6 addresses fall into the following types –Link-local addresses with prefix of FE80::/64 Similar to IPv4 APIPA /16 Can NOT be routed –Unique local addresses with prefix of FD00::/8 Similar to IPv4 Private IP Can only be routed Internally –Global addresses Similar to IPv4 Public IP First 3 bits are always 001, followed by 45 bits global routing prefix, then followed by 16 bits Internal Subnet ID Last 64 bits Interface ID (host ID) –Multicast addresses with prefix of FF00::/8 –Special addresses

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IPv6 Client Configuration Autoconfiguration: –2008 generates Link-Local Address –Then, contacts a local router for Network Configuration Stateless: Client generates Global Address Stateful: Client accepts ip address from DHCP server –When no router & DHCP  NO Global Address DHCPv6 –Provide secondary Network Configuration Info. such as DNS server IP address Neighbor Discovery –Used by IPv6 clients for router discovery on a network 15

Upgrading Your Network to IPv6 Dual-Layer IP stack –2008 uses dual-layer TCP/IP Stack architecture IPv6 over IPv4 –Encapsulate IPv6 in IPv4 packet –Tunnels that can be created Router-to-router Host-to-router and router-to- host Host-to-host ISATAP 6to4 Teredo 16

ISATAP Allows IPv6 routers and hosts to communicate across IPv4 networks Used for two IPv6 hosts communicate through Private IPv4 network Requires a router that supports ISATAP Interface ID is separated into two parts –First 32 bits are either 0:5efe for a private address or 200:5efe for a public address –Last 32 bits are the IPv4 address netsh commands netsh interface isatap show state netsh interface isatap set state enabled netsh interface isatap set state disabled 17

6to4 Uses tunneling of IPv6 packets over an IPv4 network Used for IPv6 companies to connect Internet via IPv4 ISP provider Stores the IPv4 address of the ISATAP router in bits 17 to 48 Encapsulates only the IPv4 router’s IP address, not the destination client 18

Teredo Allows IPv6 hosts to communicate over IPv4 networks that use NAT Works only with NAT implementations that support UDP port translation Should always be implemented with a client-based stateful firewall netsh commands to view Teredo status netsh interface ipv6 show teredo netsh interface teredo show state To enable Teredo for workgroup clients netsh interface ipv6 set teredo client To enable Teredo for Active Directory clients netsh interface ipv6 set teredo enterpriseclient 19

Disabling IPv6 For a specific network adapter –You can disable IPv6 using the Network Connections window and by editing the Registry To use the Registry to disable all of IPv6 on a computer, create the following Registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSe t\Services\TCPIP6\Parameters\ DisabledComponents 20

Troubleshooting TCP/IP Networking Ipconfig –Displays the current IP configuration on your local client –Ipconfig /all command A good way to start troubleshooting clients that have problems accessing network resources Ping –Utility that determines whether a target host is on and responding to communication –Works by sending an ICMP echo request packet to the target 21

Troubleshooting TCP/IP Networking (continued) Pathping –Used to map the hops a packet must make to reach a target Tracert –Command-line tool for tracing the route between two nodes Netstat –Command-line tool for displaying network connection information such as routing tables 22