Day 14 TCP/IP Fundamental- TCP/IP Model, IP Addressing TCP/IP Configuration
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...
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
OV 7 - 2Copyright © 2013 Logical Operations, Inc. All rights reserved.
Static and Dynamic IP Addressing
DHCP Server Static IP addressingStatic IP addressing
Dynamic IP addressingDynamic IP addressing
DHCP Client
DHCP Client
OV 7 - 3Copyright © 2013 Logical Operations, Inc. All rights reserved.
Static IP Address Assignment
OV 7 - 4Copyright © 2013 Logical Operations, Inc. All rights reserved.
DHCP
192.168.100.150
192.168.100.152
192.168.100.151
DHCP Server
OV 7 - 5Copyright © 2013 Logical Operations, Inc. All rights reserved.
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
OV 7 - 6Copyright © 2013 Logical Operations, Inc. All rights reserved.
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.
OV 7 - 7Copyright © 2013 Logical Operations, Inc. All rights reserved.
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
OV 7 - 8Copyright © 2013 Logical Operations, Inc. All rights reserved.
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.
OV 7 - 9Copyright © 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 7 - 10Copyright © 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 7 - 11Copyright © 2013 Logical Operations, Inc. All rights reserved.
Sockets
{tcp , 193.44.234.3 , 53}
Local IP addressLocal IP address
ProtocolProtocol Port numberPort number
OV 7 - 12Copyright © 2013 Logical Operations, Inc. All rights reserved.
Host Names
server03.ourglobalcompany.com
Fully Qualified Domain Name
(FQDN)
Fully Qualified Domain Name
(FQDN)
Domain nameDomain nameHost nameHost name
OV 7 - 13Copyright © 2013 Logical Operations, Inc. All rights reserved.
DNS
.com .org
ourglobalcompany.com citizensinfo.orgeverythingforcoffee.com
OV 7 - 14Copyright © 2013 Logical Operations, Inc. All rights reserved.
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.
OV 7 - 15Copyright © 2013 Logical Operations, Inc. All rights reserved.
The DNS Hierarchy
“.” Root
.gov .com .edu .org
books training
everythingforcoffee ourglobalcompany citizensinfo
FQDN = training.ourglobalcompany.com
OV 7 - 16Copyright © 2013 Logical Operations, Inc. All rights reserved.
The DNS Name Resolution Process
OV 7 - 17Copyright © 2013 Logical Operations, Inc. All rights reserved.
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.
OV 7 - 18Copyright © 2013 Logical Operations, Inc. All rights reserved.
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.
OV 7 - 19Copyright © 2013 Logical Operations, Inc. All rights reserved.
The HOSTS File
At least one spaceAt least one space
IP addressIP address Host nameHost name
OV 7 - 20Copyright © 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
Total number of hops to
remote host
Routers in trace path to destination
Routers in trace path to destination
Response time at each router
Response time at each router
OV 7 - 21Copyright © 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 7 - 22Copyright © 2013 Logical Operations, Inc. All rights reserved.
The pathping Command (Cont.)
Total number of hops to
remote host
Total number of hops to
remote host
Network statisticsNetwork statistics
OV 7 - 23Copyright © 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 7 - 24Copyright © 2013 Logical Operations, Inc. All rights reserved.
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
OV 7 - 25Copyright © 2013 Logical Operations, Inc. All rights reserved.
NTP
09:21:40:23
NTP
Master clock
System clockSystem clock
OV 7 - 26Copyright © 2013 Logical Operations, Inc. All rights reserved.
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
OV 7 - 27Copyright © 2013 Logical Operations, Inc. All rights reserved.
POP3
POP3
Email serverEmail client
Used to retrieve email messages from a mailbox Used to retrieve email messages from a mailbox
OV 7 - 28Copyright © 2013 Logical Operations, Inc. All rights reserved.
IMAP4
IMAP4
Used to retrieve email messages from a mail serverUsed to retrieve email messages from a mail server
OV 7 - 29Copyright © 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 7 - 30Copyright © 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
Web browser formats the content received from the server
and displays it on the client
OV 7 - 31Copyright © 2013 Logical Operations, Inc. All rights reserved.
HTTPS
SSL
OV 7 - 32Copyright © 2013 Logical Operations, Inc. All rights reserved.
NFS
UNIX Windows
Enables users to access shared files
across multiple operating systems
Enables users to access shared files
across multiple operating systems
OV 7 - 33Copyright © 2013 Logical Operations, Inc. All rights reserved.
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
OV 7 - 34Copyright © 2013 Logical Operations, Inc. All rights reserved.
SCP
SCP
Uses SSH to copy file securely between local and remote hostUses SSH to copy file securely between local and remote host
OV 7 - 35Copyright © 2013 Logical Operations, Inc. All rights reserved.
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
OV 7 - 36Copyright © 2013 Logical Operations, Inc. All rights reserved.
SMB
TCP/IPNetBIOS
Helps share resources among
computers
Helps share resources among
computers
OV 7 - 37Copyright © 2013 Logical Operations, Inc. All rights reserved.
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
OV 7 - 38Copyright © 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 7 - 39Copyright © 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?