OV Copyright © 2013 Logical Operations, Inc. All rights reserved. TCP/IP Services  Assign IP Addresses  Domain Naming Services  TCP/IP Commands  Common TCP/IP Protocols  TCP/IP Interoperability Services

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Static and Dynamic IP Addressing DHCP Server Static IP addressing Dynamic IP addressing DHCP Client

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Static IP Address Assignment

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. DHCP DHCP Server

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The DHCP Lease Process DHCP discovery DHCP offer DHCP request DHCP ACK DHCP ServerDHCP Client Node comes online 1 1 Unused DHCP offers expire 6 6

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The DHCP Lease Process (Cont.) StepDescription Step 1: Node comes online A node configured to use DHCP comes online and loads a simple version of TCP/IP. Step 2: DHCP discovery After a node comes online and is ready to communicate with a DHCP server, it transmits a Bootstrap Protocol (BOOTP) broadcast, called a DHCP discover, to the network's broadcast address of to check if any DHCP servers are online, and request an IP address. Step 3: DHCP offer DHCP servers that are online respond with a directed lease offer packet that contains an IP address that the node can lease. Step 4: DHCP request The node accepts the first offer it receives, and returns a request to lease the IP address from the DHCP server, called a DHCP request. Step 5: DHCP ACK The DHCP server acknowledges the request from the node with a DHCP ACK, that has the IP address and settings required for the leasing time and starts the lease. The DHCP server also updates the IP address in its database as being in use to avoid reassigning the address. Step 6: Unused DHCP offers expire When the unused offers expire, all the other DHCP servers return the offered IP addresses to the common pool in their DHCP scopes.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. APIPA DHCP IP address assignment unavailable DHCP server APIPA allows communication without DHCP

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. IP Configuration Utilities UtilityDescription ipconfig  Displays connection-specific DNS suffix, IP address, subnet mask, and default gateway information. Must be run from a command line.  Supported on server systems including Windows Server 2008 and Windows Server 2008 R2, and client systems including Windows Vista, Windows XP, Windows NT, and Novell NetWare. ifconfig  Displays the status of currently active network interface devices. Using options, you can dynamically change the status of the interfaces and their IP address.  Supported on Linux and UNIX. dhclient  Allows you to configure and manage DHCP settings for the network interfaces of a computer.  Supported on Linux and UNIX.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The ping Command  Verify the network connectivity of a computer  Check if the target system is active  Checks the host name, IP address, and reachability of the remote system by using and listening for echo replies

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Ports A port is:  An endpoint of a logical TCP or UDP connection  Numbered from 0 to 65,535  Split into three blocks:  Well-known ports – preassigned to system processes by IANA  Registered ports – available to user processes and are listed as a convenience by IANA  Dynamic ports – assigned by a client operating system as needed when there is a request for the service.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Sockets {tcp, , 53} Local IP address Protocol Port number

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Host Names server03.ourglobalcompany.com Fully Qualified Domain Name (FQDN) Domain name Host name

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. DNS.com.org ourglobalcompany.comcitizensinfo.org everythingforcoffee.com

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Types of DNS Records Record TypePurpose Address (A) Maps a host name to its IP address using a 32-bit IPv4 address. IPv6 address (AAAA) Maps a host name to its IP address using a 128-bit IPv6 address. Canonical name (CNAME) Maps multiple canonical names (aliases) to an A record. Mail Exchange (MX)Maps a domain name to a mail exchange server list. Name Server (NS) Delegates a DNS zone access to the given authoritative name servers. Pointer (PTR) Maps an IP address to the host name for the purpose of reverse lookup. Start of Authority (SOA)Specifies authoritative information about a DNS zone. Service Locator (SRV)Specifies a generic service location record of newer products.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The DNS Hierarchy “.” Root.gov.com.edu.org bookstraining everythingforcoffeeourglobalcompanycitizensinfo FQDN = training.ourglobalcompany.com

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The DNS Name Resolution Process

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The DNS Name Resolution Process (Cont.) Process StepDescription Step 1: Client request When a client needs to resolve a DNS name, it sends a name resolution request to the DNS resolver. A DNS name resolution request message is generated by the resolver, which is transmitted to the DNS server address specified during configuration. Step 2: Preferred DNS server The DNS server, upon receiving the request, checks if the requested name is in its DNS cache entries or its local DNS database, and returns the IP address to the client. If there is no match for the requested name, the DNS server forwards the request to a root name server asking which DNS server has the entries for the appropriate top-level domain. Step 3: Root name server Upon receiving the request, the root name server, reads the top-level domain of the requested name and replies with a message that contains the IP address of the server for that top-level domain. The root name server then sends the reply back to the client’s DNS server.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The DNS Name Resolution Process (Cont.) Process StepDescription Step 4: Top-level domain server The client’s DNS server contains the IP address of the top-level domain of the requested name. The DNS server then contacts the top-level domain's DNS server to resolve the name. The top-level domain server reads the second-level domain of the requested name, and if it can resolve the name, it sends the desired IP address back to the client’s DNS server. Step 5: Other domain servers If the top-level domain cannot resolve the name because of additional levels in the FQDN, it sends the IP address to the second- level DNS server. Step 6: Host name resolution This communication between DNS servers continues until it reaches the level in the DNS hierarchy where a DNS server can resolve the host name. Step 7: Host address The preferred DNS server provides the client with the IP address of the target host.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The HOSTS File At least one space IP address Host name

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The tracert Command Determines the route data takes to reach the destination. Total number of hops to remote host Routers in trace path to destination Response time at each router Response time at each router

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The pathping Command  pathping combines the functionality of the ping and tracert commands.  Provides information about latency and packet loss on a network.  Similar to ping, pathping sends multiple ICMP echo request messages to each router between two hosts over a period of time, and then displays results based on the number of packets returned by each router.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The pathping Command (Cont.) Total number of hops to remote host Network statistics

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. The MTR Utility My traceroute (MTR) utility:  Combines the functionality of the ping and traceroute commands.  Show a list of the routers traversed, the average round trip time, and packet loss of each router.  Allows network administrators to identify latency or packet loss between two routers.  Is used on Unix-based systems.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. FTP FTP DaemonFTP Utility Enables transfer of files between a user’s workstation and a remote host

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. NTP 09:21:40:23 NTP Master clock System clock

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. SMTP server client Used to format and send messages from a client to a server

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. POP3 server client Used to retrieve messages from a mailbox

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. IMAP4 Used to retrieve messages from a mail server

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. NNTP Network News Transfer Protocol (NNTP):  Is used to post and retrieve messages from the worldwide bulletin board system called USENET.  Only submits and retrieves new or updated news articles from the server.  Forms the base for RSS feeds, which allow users to subscribe to and receive updates made to web pages.

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. HTTP Web serverWeb client Web browser formats the content received from the server and displays it on the client

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. HTTPS SSL

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. NFS UNIXWindows Enables users to access shared files across multiple operating systems

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. SSH slogin Password is encrypted The entire login session is encrypted and protected against attacks

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. SCP Uses SSH to copy file securely between local and remote host

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Telnet C:\> telnet Password:***** Enables a user at one site to simulate a session on a remote host

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. SMB TCP/IP NetBIOS Helps share resources among computers

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. LDAP LDAP serverDNS server LDAP servers store directory data DNS locates LDAP servers LDAP/DNS client

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Zeroconf A set of standards that provides for automatic configuration and IP address on both Ethernet and wireless networks. Zeroconf technology networks must include methods for four functions:  Network-layer address assignment  Automatic multicast address assignment  Name/address resolution  Discovery of network services

OV Copyright © 2013 Logical Operations, Inc. All rights reserved. Reflective Questions 1. What TCP/IP services and utilities do you currently implement in your organization? 2. Which TCP/IP command will you use commonly on your network?