Chương 7 - Thực hiện Dịch vụ IP potx

1 Chapter 7 - Implementing IP Addressing Services CCNA Exploration 4.0 Học viện mạng Bach Khoa - Website: www.bkacad.com 2 Introduction Học viện mạng Bach Khoa - Website: www.bkacad.com 3 DHCP Học viện mạng Bach Khoa - Website: www.bkacad.com 4 Introducing DHCP  DHCP assigns IP addresses and other important network configuration information dynamically. Học viện mạng Bach Khoa - Website: www.bkacad.com 5 DHCP Operation • Manual Allocation: The administrator assigns a pre- allocated IP address to the client and DHCP only communicates the IP address to the device. • Automatic Allocation: DHCP automatically assigns a static IP address permanently to a device, selecting it from a pool of available addresses. There is no lease and the address is permanently assigned to a device. • Dynamic Allocation: DHCP automatically dynamically assigns, or leases, an IP address from a pool of addresses for a limited period of time chosen by the server, or until the client tells the DHCP server that it no longer needs the address. Học viện mạng Bach Khoa - Website: www.bkacad.com 6 BOOTP and DHCP • Both DHCP and BOOTP are client/server based and use UDP ports 67 and 68. Those ports are still known as BOOTP ports. Học viện mạng Bach Khoa - Website: www.bkacad.com 7 DHCP Message Format Học viện mạng Bach Khoa - Website: www.bkacad.com 8 DHCP Discover Học viện mạng Bach Khoa - Website: www.bkacad.com 9 DHCP Offer Học viện mạng Bach Khoa - Website: www.bkacad.com 10 Configuring a DHCP Server [...]... L2 Broadcast RTA(config)#interface e0 RTA(config-if) #ip helper-address 172 .24.1.255 RTA(config)#interface e3 RTA(config-if) #ip directed-broadcast Học viện mạng Bach Khoa - Website: www.bkacad.com 21 Using helper addresses • By default, the ip helper-address command forwards the eight UDPs services • The Cisco IOS provides the global configuration command ip forwardprotocol to allow an administrator to... not convert the logical broadcast 172 .24.1.255 into a physical broadcast with a Layer 2 address of FF-FF-FF-FF-FFFF To allow all the nodes in the server farm to receive the broadcasts at Layer 2, e3 will need to be configured to forward directed broadcasts with the following command: RTA(config)#interface e3 RTA(config-if) #ip directed-broadcast Học viện mạng Bach Khoa - Website: www.bkacad.com 20 DHCP... • Overloading – A form of dynamic NAT that maps multiple unregistered IP addresses to a single registered IP address (many-to-one) by using different ports Known also as PAT (Port Address Translation), single address NAT or port-level multiplexed NAT Học viện mạng Bach Khoa - Website: www.bkacad.com 33 NAT Example • • • • Inside local address – The IP address assigned to a host on the inside network... Problem Học viện mạng Bach Khoa - Website: www.bkacad.com 17 DHCP Relay Host Renew Học viện mạng Bach Khoa - Website: www.bkacad.com 18 DHCP Relay Broadcast Unicast • Helper address configuration that relays broadcasts to all servers on • the segment RTA(config)#interface e0 RTA(config-if) #ip helper-address 172 .24.1.255 But will RTA forward the broadcast? Học viện mạng Bach Khoa - Website: www.bkacad.com... viện mạng Bach Khoa - Website: www.bkacad.com 27 Private and Public IP Addressing Học viện mạng Bach Khoa - Website: www.bkacad.com 28 What is NAT ? Học viện mạng Bach Khoa - Website: www.bkacad.com 29 NAT Terminology • • • • Inside local address - Usually not an IP address assigned by a RIR or service provider and is most likely an RFC 1918 private address Inside global address - Valid public address... Khoa - Website: www.bkacad.com 30 The Forms of NAT • Dynamic NAT – Maps an unregistered IP address to a registered IP address from a group of registered IP addresses Dynamic NAT also establishes a one-to-one mapping between unregistered and registered IP address, but the mapping could vary depending on the registered address available in the pool, at the time of communication Học viện mạng Bach Khoa -. .. - Website: www.bkacad.com 11 Verifying DHCP PC1: ipconfig /all Học viện mạng Bach Khoa - Website: www.bkacad.com 12 Verifying DHCP PC2: ipconfig /all Học viện mạng Bach Khoa - Website: www.bkacad.com 13 Verifying DHCP Học viện mạng Bach Khoa - Website: www.bkacad.com 14 Configuring a DHCP Client Học viện mạng Bach Khoa - Website: www.bkacad.com 15 Configuring a DHCP Client Học viện mạng Bach Khoa -. .. server at 209.165.201.1, router R2 must translate the address In this case, IP address 209.165.200.226 is used as the inside global address for PC1 Outside global address - Reachable IP address assigned to a host on the Internet – For example, the web server is reachable at IP address 209.165.201.1 Outside local address - The local IP address assigned to a host on the outside network In most situations,... Học viện mạng Bach Khoa - Website: www.bkacad.com 22 Configuring a DHCP Server Using SDM Học viện mạng Bach Khoa - Website: www.bkacad.com 23 Configuring a DHCP Server Using SDM Học viện mạng Bach Khoa - Website: www.bkacad.com 24 Verifying and Troubleshooting DHCP Học viện mạng Bach Khoa - Website: www.bkacad.com 25 Verifying and Troubleshooting DHCP Học viện mạng Bach Khoa - Website: www.bkacad.com... routable or public) IP address assigned the service provider that represents one or more inside local IP addresses to the outside world Outside local address – The IP address of an outside host as it is known to the hosts on the inside network Outside global address – The IP address assigned to a host on the outside network The owner of the host assigns this address Học viện mạng Bach Khoa - Website: www.bkacad.com . that the router will not convert the logical broadcast 172 .24.1.255 into a physical broadcast with a Layer 2 address of FF-FF-FF-FF-FF- FF. • To allow all the nodes in the server farm to receive. segment. RTA(config)#interface e0 RTA(config-if) #ip helper-address 172 .24.1.255 • But will RTA forward the broadcast? Broadcast Unicast Học viện mạng Bach Khoa - Website: www.bkacad.com 20 DHCP Relay •. 1 Chapter 7 - Implementing IP Addressing Services CCNA Exploration 4.0 Học viện mạng Bach Khoa - Website: www.bkacad.com 2 Introduction Học viện mạng Bach Khoa - Website: www.bkacad.com