Network Guide to Networks 5th Edition

1. Network+ Guide to Networks5th Edition Chapter 10 In-Depth TCP/IP Networking

2. Network+ Guide to Networks, 5th Edition 2 Objectives Understand methods of network design unique to TCP/IP networks, including subnetting, and address translation Explain the differences between public and private TCP/IP networks Describe protocols used between mail clients and mail servers, including SMTP, POP3, and IMAP4 Employ multiple TCP/IP utilities for network discovery and troubleshooting

3. Network+ Guide to Networks, 5th Edition 3 TCP/IP-Based Networks TCP/IP protocol suite use Public Internet connectivity Private connection data transmission TCP/IP fundamentals IP: routable protocol Interfaces requires unique IP address Node may use multiple IP addresses Two IP versions: IPv4 and IPv6 IPv4: older; more common

4. Network+ Guide to Networks, 5th Edition 4 TCP/IP-Based Networks (cont’d.) IPv4 addresses Four 8-bit octets (dotted decimal represents 32 bits) Network hostname/address assignments Dynamic (DHCP) Static (manually assigned) Network classes: A, B, C Subnetting

5. Network+ Guide to Networks, 5th Edition 5 Classful Addressing in IPv4 Simplest IPv4 addressing type Developed in the 1960s Adheres to network class distinctions Recognizes Class A, B, C addresses

6. Network+ Guide to Networks, 5th Edition 6 Reserved Addresses Cannot be assigned to host devices(PCs, servers, printers, etc.) Network Address – all host bits set to 0 Broadcast address – all host bits set to 1

7. Network+ Guide to Networks, 5th Edition 7 Subnetting Developed in the 1980s Separates network into multiple logically defined segments (subnets) Subnets are separated by routers  Reasons to subnet: Enhance security Improve performance Simplify troubleshooting

8. Network+ Guide to Networks, 5th Edition 8 IPv4 Subnet Masks 32-bit, dotted-decimal notation Identifies how IP Address was divided (aka by Jeff as the “bit split”) Indicates where network information located Subnet mask bits 1: network bit 0: host bit

9. Network+ Guide to Networks, 5th Edition 9 IPv4 Subnet Masks (cont’d.) Network class Associated with default subnet mask

10. Network+ Guide to Networks, 5th Edition 10 IPv4 Subnetting Divides classful (A, B, C) networks into several smaller “subnets” by changing the “bit-split.” How many subnets will result? SN = 2snb snb: number of host-bits “borrowed” SN: number of resulting subnets How many hosts/subnet will result? H = 2hb - 2 hb: number of host-bits remaining H: number of resulting hosts/subnet

11. Network+ Guide to Networks, 5th Edition 11 Address Translation Reasons for using address translation Scalability: overcome IPv4 address quantity limitations Security: “Hide” your network from the Internet NAT (Network Address Translation) Gateway replaces client’s private IP address with Internet-recognized IP address

12. Network+ Guide to Networks, 5th Edition 12 Address Translation (cont’d.) DNAT (Dynamic Network Address Translation) Also called IP masquerading Internet-valid IP address might be assigned to any client’s outgoing transmission SNAT (Static Network Address Translation) Client associated with one private IP address, one public IP address Never changes Useful when operating mail server

13. Network+ Guide to Networks, 5th Edition 13 Address Translation (cont’d.) PAT (Port Address Translation) Each client session with server on Internet assigned separate TCP port number Client server request datagram contains port number Internet server responds with datagram’s destination address including same port number

14. Network+ Guide to Networks, 5th Edition 14 Address Translation (cont’d.)

15. Network+ Guide to Networks, 5th Edition 15 E-Mail Protocols SMTP -- responsible for sending e-mail from one mail server to another over TCP/IP-based networks Uses TCP port 25 Drawback: 1000 ASCII character limit POP3 -- retrieves e-mail from server Uses TCP port 110 IMAP4 -- good for mobile users Uses TCP port 143 Other protocols can be used too

16. Network+ Guide to Networks, 5th Edition 16 Additional TCP/IP Utilities TCP/IP transmission process has many points of failure, which increase with network size, distance Utilities will: Help track down most TCP/IP-related problems Help discover information about node, network On Windows PCs, most TCP/IP utilities are “DOS” commands

17. Network+ Guide to Networks, 5th Edition 17 Additional TCP/IP Utilities (cont’d.) ipconfig -- displays NIC’s IP address, subnet mask, default gateway, etc. netstat -- displays TCP/IP statistics, component details, host connections Nbtstat -- displays NetBIOS statistics, resolves NetBIOS names to IP addresses, but has limited use as TCP/IP diagnostic utility

18. Additional TCP/IP Utilities (cont’d.) Ping – basic connectivity test Pathping – simple replies received from all routers between host and destination nodes Tracert -- detailed replies received from all routers between host and destination nodes

19. Network+ Guide to Networks, 5th Edition 19 Additional TCP/IP Utilities (cont’d.) hostname -- displays PC’s host name nslookup -- queries DNS database and displays host name for a given IP address whois -- queries DNS registration database and displays organization/domain information