© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE I Chapter 6 1 Implementing IP Addressing Services Accessing the WAN – Chapter 7

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 2 Objectives  Configure DHCP in an enterprise branch network  Configure NAT on a Cisco router  Configure new generation RIP (RIPng) to use IPv6

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 3 Configure DHCP in an Enterprise Branch Network  Describe the function of DHCP in a network Dynamic Host Configuration Protocol

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 4 Configure DHCP in an Enterprise Branch Network  Describe how DHCP dynamically assigns an IP address to a client

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 5 Configure DHCP in an Enterprise Branch Network  Describe the differences between BOOTP and DHCP

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 6 DHCP structure

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 7 Configure DHCP in an Enterprise Branch Network

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 8 Verifying DHCP

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 9 Configure DHCP in an Enterprise Branch Network

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 10 DHCP Relay

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 11 DHCP via SDM

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 12 Public vs. Private IP addressess

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 13 Network Address Translation

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 14 Types of NAT Static NAT (one-to-one) mapping Dynamic NAT (N to M) mapping Overloading (PAT) (N to one-or-many) mapping

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 15 Configure NAT on a Cisco Router

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 16 Configure static NAT (one-to-one) GW(config)# interface e0 GW(config-if)# ip address GW(config-if)# ip nat inside GW(config-if)# no shutdown GW(config)# interface e1 GW(config-if)# ip address GW(config-if)# ip nat outside GW(config-if)# no shutdown /24 Routed /24 GW(config)# ip nat inside source static

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 17 Configure dynamic NAT (N to M) Configure NAT pool R(config)# ip nat pool Name START_IP END_IP netmask MASK Configure translation ACL (which IP is allowed to be translated) R(config)# ip access-list standard TRANSLATION R(config-std-nacl)# permit NETWORK WILDCARD Define dynamic translation (pair ACL and pool) R(config)# ip nat inside source list TRANSLATION pool Name Configure Inside/Outside interfaces R(config)# interface …. R(config-if)# ip nat {inside|outside}

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 18 Configure dynamic NAT (N to M) /24 Routed /24 GW(config)# interface e0 GW(config-if)# ip address GW(config-if)# ip nat inside GW(config-if)# no shutdown GW(config)# interface e1 GW(config-if)# ip address GW(config-if)# ip nat outside GW(config-if)# no shutdown GW(config)# ip nat pool PUBLIC netmask GW(config)# ip access-list standard TRANSLATION GW(config-std-nacl)# permit GW(config)# ip nat inside source list TRANSLATION pool PUBLIC

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 19 Configure overloading NAT (N to one-or-many) /24 GW(config)# interface e0 GW(config-if)# ip address GW(config-if)# ip nat inside GW(config-if)# no shutdown GW(config)# interface e1 GW(config-if)# ip address GW(config-if)# ip nat outside GW(config-if)# no shutdown GW(config)# ip nat pool PUBLIC netmask GW(config)# ip access-list standard TRANSLATION GW(config-std-nacl)# permit GW(config)# ip nat inside source list TRANSLATION pool PUBLIC overload GW(config)# ip nat inside source list TRANSLATION interface S0 overload

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 20 Port Forwarding

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 21 Troubleshooting NAT

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 22 IPv4 vs. IPv6 IPv4 address is 32 bits long There are 4,294,967,296 unique addresses Only 3.7 bilion addressess are usable for users

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 23 IPv4 vs. IPv6 IPv6 address is 128 bits long There are more than IPv4 4,294,967,296 unique addresses There are 340,282,366,920,938,463, 374,607,431,768,211,456 unique IPv6 addresses

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 24 IPv6 format

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 25 IPv6 header

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 26 IPv6 address types IPv6 Global Unicast Address Globally unique address Reserved Addresses Reserved {0000::/8, 0100::/8, 0200::/7, 0400::/6 …} Private Addresses Private use {Fe[8-F]::/12} Loopback Address Same like IPv , in IPv6 it is ::1 Unspecified Address :: (0:0:0:0:0:0:0:0)

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 27 Asigning IPv6 address Manual assignement Router(config)# interface …. Router(config-if)# ipv6 address ipv6-address/prefix-length RouterX(config-if)#ipv6 address 2001:DB8:2222:7272::72/64 EUI-64 RouterX(config-if)#ipv6 address 2001:DB8:2222:7272::/64 eui-64

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 28 Configure New Generation RIP (RIPng) to use IPv6  Describe the transition strategies for implementing IPv6

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 29 Dual stack routing

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 30 Tunneling

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 31 Dual-stack configuration

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 32 RIP new generation (RIPng)

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 33 Configure New Generation RIP (RIPng) to use IPv6  Explain how to configure and verify RIPng for IPv6

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 34 Configure New Generation RIP (RIPng) to use IPv6  Explain how to verify and troubleshoot IPv6

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 35 Summary  Dynamic Host Control Protocol (DHCP) This is a means of assigning IP address and other configuration information automatically.  DHCP operation –3 different allocation methods Manual Automatic –Steps to configure DHCP Define range of excluded addresses Create DHCP pool Configure DHCP pool specifics

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 36 Summary  DHCP Relay Concept of using a router configured to listen for DHCP messages from DHCP clients and then forwards those messages to servers on different subnets  Troubleshooting DHCP –Most problems arise due to configuration errors –Commands to aid troubleshooting Show ip dhcp Show run debug

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 37 Summary  Private IP addresses –Class A = 10.x.x.x –Class B = x.x – x.x –Class C = x.x  Network Address Translation (NAT) –A means of translating private IP addresses to public IP addresses –Type s of NAT Static Dynamic –Some commands used for troubleshooting Show ip nat translations Show ip nat statistics Debug ip nat

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 38 Summary  IPv6 –A 128 bit address that uses colons to separate entries –Normally written as 8 groups of 4 hexadecimal digits  Cisco IOS Dual Stack –A way of permitting a node to have connectivity to an IPv4 & IP v6 network simultaneously  IPv6 Tunneling –An IPV6 packet is encapsulated within another protocol

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 39 Summary  Configuring RIPng with IPv6 1 st globally enable IPv6 2 nd enable IPv6 on interfaces on which IPv6 is to be enabled 3 rd enable RIPng using either ipv6 rotuer rip name ipv6 router name enable

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 40