OV 7 - 1 Copyright © 2013 Logical Operations, Inc. All rights reserved. TCP/IP Services Assign IP...

OV 7 - 1Copyright © 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


Static and Dynamic IP Addressing

DHCP Server Static IP addressingStatic IP addressing

Dynamic IP addressingDynamic IP addressing

DHCP Client

DHCP Client


Static IP Address Assignment


DHCP

192.168.100.150

192.168.100.152

192.168.100.151

DHCP Server


The DHCP Lease Process

DHCP discovery

DHCP offer

DHCP request

DHCP ACK

DHCP Server DHCP Client

55

44

33

22

Node comes online11

Unused DHCP offers expire

66


The DHCP Lease Process (Cont.)

Step Description

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 255.255.255.255 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.


APIPA

169.254.16.21169.254.46.128

169.254.3.22

DHCP IP address assignment unavailable

DHCP IP address assignment unavailable

DHCP server

APIPA allows communication without DHCP

APIPA allows communication without DHCP


IP Configuration Utilities

Utility Description

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.


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


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.


Sockets

{tcp , 193.44.234.3 , 53}

Local IP addressLocal IP address

ProtocolProtocol Port numberPort number


Host Names

server03.ourglobalcompany.com

Fully Qualified Domain Name

(FQDN)

Fully Qualified Domain Name

(FQDN)

Domain nameDomain nameHost nameHost name


DNS

.com .org

ourglobalcompany.com citizensinfo.orgeverythingforcoffee.com


Types of DNS Records

Record Type Purpose

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.


The DNS Hierarchy

“.” Root

.gov .com .edu .org

books training

everythingforcoffee ourglobalcompany citizensinfo

FQDN = training.ourglobalcompany.com


The DNS Name Resolution Process


The DNS Name Resolution Process (Cont.)

Process Step Description

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.


The DNS Name Resolution Process (Cont.)

Process Step Description

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.


The HOSTS File

At least one spaceAt least one space

IP addressIP address Host nameHost name


The tracert Command

Determines the route data takes to reach the destination.

Total number of hops to

remote host


remote host

Routers in trace path to destination

Routers in trace path to destination

Response time at each router

Response time at each router


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.


The pathping Command (Cont.)


remote host


remote host

Network statisticsNetwork statistics


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.


FTP

FTP Daemon FTP Utility

Enables transfer of files between a user’s workstation and a remote hostEnables transfer of files between a user’s workstation and a remote host


NTP

09:21:40:23

NTP

Master clock

System clockSystem clock


SMTP

SMTP

Email server Email client

Used to format and send email messages from a client to a serverUsed to format and send email messages from a client to a server


POP3

POP3

Email serverEmail client

Used to retrieve email messages from a mailbox Used to retrieve email messages from a mailbox


IMAP4

IMAP4

Used to retrieve email messages from a mail serverUsed to retrieve email messages from a mail server


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.


HTTP

Web serverWeb client

Web browser formats the content received from the server

and displays it on the client

Web browser formats the content received from the server

and displays it on the client


HTTPS

SSL


NFS

UNIX Windows

Enables users to access shared files

across multiple operating systems

Enables users to access shared files

across multiple operating systems


SSH

slogin

Password is encrypted

Password is encrypted

The entire login session is encrypted and protected against attacksThe entire login session is encrypted and protected against attacks


SCP

SCP

Uses SSH to copy file securely between local and remote hostUses SSH to copy file securely between local and remote host


Telnet

Telnet

C:\> telnet 10.1.1.3Password:*****

Enables a user at one site to simulate a session on a remote hostEnables a user at one site to simulate a session on a remote host


SMB

TCP/IPNetBIOS

Helps share resources among

computers

Helps share resources among

computers


LDAP

LDAP server DNS server

LDAP servers store directory data

LDAP servers store directory data

DNS locates LDAP serversDNS locates

LDAP servers

LDAP/DNS client


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


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?

OV 7 - 1 Copyright © 2013 Logical Operations, Inc. All rights reserved. TCP/IP Services Assign IP...

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Transcript of OV 7 - 1 Copyright © 2013 Logical Operations, Inc. All rights reserved. TCP/IP Services Assign IP...