14_-_IP_Addressing_Services by xiagong0815

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									            IP addressing services


CCNA Accessing the WAN




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IP addressing services

Course objectives
By completing this course, you will:

                             Learn what is DHCP and how to
                              configure it.
                             Learn what is NAT and how to
                              configure it.
                             Learn how to configure IPv6.
IP addressing services

Course topics
These are the parts that we will approach :


                            DHCP
                            NAT & PAT
                            IPv6
IP addressing service




                    DHCP
DHCP

Preview
These are the chapters that we will approach :


 Context of DHCP
  implementation
 Comparative
  between BOOTP
  and DHCP
 DHCP Operations
 DHCP Relay
 Configuration
DHCP

Context of DHCP implementation



       Dynamic
       Host
       Configuration
       Protocol
DHCP

Context of DHCP implementation


 Server
    Company server
    Router that support DHCP




 Client
    Host with an OS
DHCP

Context of DHCP implementation


 Layer 3 configuration
     IP address and subnet mask
     Gateway address
     DNS server address
     NETBIOS server address
     Domain name
     …
DHCP

Context of DHCP implementation


 Lease notion


    Assign a temporary configuration limited by time
    Duration defined by the server
    Need for renewal
DHCP

Context of DHCP implementation

 Automatic allocation
    Dynamic
    Permanent
 Manual allocation
    Static
    Permanent
 Dynamic allocation
    Dynamic
    Temporary
DHCP

Comparative between BOOTP and DHCP


 BOOT Strap Protocol
 Used by machine without HDD
 Assign a layer 3 configuration
 4 parameters only
DHCP

Comparative between BOOTP and DHCP


 DHCP is based on BOOTP
 Similarities
     Use port UDP 67 (server) et 68 (client)‫‏‬
     Assign one address IP and subnet mask
     Assign one gateway address
     Assign one DNS server address
DHCP

Comparative between BOOTP and DHCP


 Differences
    DHCP use lease method
    DHCP assign dynamically (or statically)‫‏‬
    DHCP have more than 30 configuration options


    BOOTP assign statically only
    BOOTP have only 4 configuration options
DHCP

Comparative between BOOTP and DHCP


 Client – Server protocol
     Demand of services by the client
     Answer by server
 Request on BOOTP port
     UDP
     Server port : 67
     Client port : 68
DHCP

DHCP Operations


 Operation realized in 4 stages
     DHCP DISCOVER
     DHCP OFFER
     DHCP REQUEST
     DHCP ACK
DHCP

DHCP Operations


 DHCP DISCOVER
    Demand from client to server(s)‫‏‬
    Request send in broadcast
 DHCP OFFER
    Offer from server(s) to client
    Request send in unicast
    Contain all configuration information
DHCP

DHCP Operations


 DHCP REQUEST
    Confirmation from client to server(s)‫‏‬
    Request send in broadcast
    May be a renew of lease demand
 DHCP ACK
    Confirmation from serveur to client
    Request send in unicast
    Autorize the client to use the configuration
DHCP

DHCP Operations


                                      DHCP 1

            DISCOVER (Broadcast)‫‏‬


           DHCPOFFER 1 (Unicast)‫‏‬

           DHCPOFFER 2 (Unicast)‫‏‬


         DHCP REQUEST (Broadcast)‫‏‬


                                     DHCP 2
            DHCPACK 1 (Unicast)‫‏‬
DHCP

DHCP Operations

 DHCP DECLINE
    Sent by the client
    Detection on the segment that the IP is already used
    Renew the process
 DHCP NACK
    Sent by the server
    Detection on the segment that the IP is already used
    Renew the process
 DHCP RELEASE
    Release of the IP by the client
DHCP

DHCP Relay


 DHCP client request send in broadcast


 Broadcast stopped by routers


 Need to transmit broadcast beyond this segment
DHCP

DHCP Relay




   DHCP server
   10.0.0.1



                 F 0/0




                         DHCP DISCOVER
                           (Broadcast)‫‏‬   IP = ?
DHCP

DHCP Relay

 Configure ip helper-address on the interface
    Interface configuration mode
    Relay UDP broadcast to unicast address
    Work for several services
        DHCP
        DNS
        Time Protocol
        TACACS
        TFTP
        NetBIOS
DHCP

DHCP Relay


                             Router(config)#interface FastEthernet 0/0
               DHCP DISCOVER Router(config-if)#ip helper-address 10.0.0.1
                  (Unicast)‫‏‬


 DHCP server
   10.0.0.1



                          F 0/0




                                       DHCP DISCOVER
                                         (Broadcast)‫‏‬       IP = ?
DHCP

Configuration


 ip dhcp pool {name}
    Global configuration mode
    Change in DHCP configuration mode
    Create a group of IP range




       Router(config)# ip dhcp pool test
       Router(config-dhcp)#
DHCP

Configuration


 network {prefix} {mask}
    DHCP configuration mode
    Indicate the IP range available

       Router(config-dhcp)# network 172.16.0.0 255.255.0.0
       Router(config-dhcp)# network 192.168.2.0 255.255.255.0
DHCP

Configuration


 lease {infinite | days [hours] [minutes] }
     DHCP configuration mode
     Specify duration of the lease
     Default value : 1 day

       Router(config-dhcp)# lease 3 12 30
DHCP

Configuration


 ip dhcp excluded-address {prefix 1} [prefix 2]
    Global configuration mode
    Exclude an address from the pool
    We can exclude a range

 Router(config)# ip dhcp excluded-address 172.16.0.1
 Router(config)# ip dhcp excluded-address 192.168.2.1 192.168.2.10
DHCP

Configuration


 default-router {prefix}
     DHCP configuration mode
     Specify the default gateway


 dns-server {prefix} [prefix2, prefix3,‫]…‏‬
     DHCP configuration mode
     Specify DNS server(s)‫‏‬

  Router(config-dhcp)# default-router 192.168.2.254
  Router(config-dhcp)# dns-server 201.184.172.56 201.184.198.2
DHCP

Configuration


 netbios-name-server {prefix}
    DHCP configuration mode
    Specify NETBIOS WINS server address


 domain-name {name}
    DHCP configuration mode
    Specify domain name

       Router(config-dhcp)# netbios-name-server 10.0.0.5
       Router(config-dhcp)# domain-name cisco-lab
DHCP

Configuration


 ip helper-address {prefix}
    Interface configuration mode
    Relay UDP broadcast to specific unicast address
    We can specify several address

       Router(config)# interface serial 0/0
       Router(config-if)# ip helper-address 10.0.0.1
       Router(config-if)# ip helper-address 10.1.0.5
DHCP

Configuration




       Router(config)# ip dhcp pool test
       Router(config-dhcp)# network 172.16.0.0 255.255.0.0
       Router(config-dhcp)# default-router 172.16.255.254
       Router(config-dhcp)# lease infinite
       Router(config-dhcp)# dns-server 10.0.0.1
       Router(config-dhcp)# netbios-name-server 10.0.0.23
       Router(config-dhcp)# exit
       Router(config)# ip dhcp-excluded address 172.16.255.254
       Router(config)# interface fastethernet 0/0
       Router(config-if)# ip helper-address 10.0.0.23
DHCP

Configuration

 Show ip dhcp binding
     Privileged mode

 Router#show ip dhcp binding

 IP address    Hardware address     Lease expiration Type
 172.16.12.11 0100.10a4.188f.c9 Mar 02 1993 01:25 AM Automatic
 172.16.12.31 0100.0ae6.bbcf.8d     Mar 02 1993 01:25 AM Automatic



 Show ip dhcp server statistics
     Privileged mode
     DHCP Request sent and received
DHCP

Part 1 Stop-and-think
Do you have any questions ?
IP addressing services




                    NAT & PAT
NAT & PAT

Preview
These are the chapters that we will approach :


 Terminology
 Principe of NAT
NAT & PAT

Terminology

     Network
     Address
     Translation
     Port
     Address
     Translation
NAT & PAT

Terminology

    Local address – Private IP address
    used in internal (inside) part of the
    network.
    ► LAN of an office


    Global address – Public IP address
    used in external (outside) part of the
    network.
     ► Internet
NAT & PAT

Terminology



     Local address   Global address



                       INTERNET




       Inside           Outside
NAT & PAT

Terminology
 Global address
     Outside Global Address
         IP address assigned to a host from an external network

     Inside Global Address
         IP address assigned by an ISP to represent LAN on Internet



 Local address
     Inside Local Address
         IP address assigned in the LAN

     Outside Local Address
         IP address of a host from an external network which is known
          by users of the internal network
NAT & PAT

Terminology



  Inside local       Inside global                Outside global



                                     INTERNET




     Local address               Global address
NAT & PAT

Note
NAT & PAT

Principe of NAT


 There are 2 types of NAT
     Static
     Dynamic


 There is another type : PAT (Port Address Translation)‫‏‬
NAT & PAT

Principe of NAT

 Static NAT
     Use to map inside local address with global inside
      address


     Use for local server that must be visible from Internet
NAT & PAT

Principe of NAT
 The host with IP address 192.168.1.3 will be forever
  translated as 202.67.3.8

 The host with IP address 192.168.1.4 will be forever
  translated as 202.67.3.9

192.168.1.3
              192.168.1.3          202.67.3.8


                                                 INTERNET




              192.168.1.4          202.67.3.9
192.168.1.4
NAT & PAT

Principe of NAT

 Dynamic NAT
     Each user of the LAN will have one global adress
      within the address pool


     Mapping is automatic


     Overloading or PAT can assign more than one user
      with the same global IP adress with the help of the
      port number
NAT & PAT

Principe of NAT
 Each inside local IP address will be translated with the
  first public IP address available in the public IP address
  pool.



192.168.1.3
              192.168.1.3            202.67.3.11


                                                    INTERNET




              192.168.1.4            202.67.3.14
192.168.1.4
NAT & PAT

Principe of NAT

 Only one IP address will be assigned for several users


 Each user will have a different port number (coded on 16
  bits), to be differenced


 65536 local IP can in theory be assigned for one external
  IP


 In reality : no more than 4000 IP
NAT & PAT

Principe of NAT
 Each IP Address of the local network will be translated on
  the same IP with a different port number




192.168.1.3
              192.168.1.3        202.67.3.10:5401


                                                    INTERNET




              192.168.1.4        202.67.3.10:5402
192.168.1.4
NAT & PAT

Principe of NAT

 The PAT will try to conserve the port number source
  assigned by the local host
 If the port number is already used by another user
     The PAT will assign the first free port number in the
      pool that correspond to the source port
         0-511
         512-1023
         1024-65535
 If any port number is free, and if another public IP address
  is available, the PAT will try the process with it.
NAT & PAT

Part 2 Stop-and-think
 Do you have any questions ?
IP Addressing Services

Course summary



                         DHCP




          NAT & PAT
      Congratulations
You have successfully completed
  the SUPINFO course module
            n°07
   IP Addressing Services
IP Addressing Services

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