Cisco ICND1

5.0 IP Services

  • 5.1 Configure and verify DHCP (IOS router)

    The Dynamic Host Configuration Protocol (DHCP) is a network configuration protocol that enables a server on an IP network to automatically assign an IP address to a computer from a predetermined range of numbers. The most essential information needed is an IP address, and a default route and routing prefix. DHCP controls the assignment of unique dynamic IP addresses and routing information, eliminating the manual task by a network administrator.

    • 5.1.a Configuring router interfaces to use DHCP

      The Dynamic Host Configuration Protocol (DHCP) uses a UDP-based broadcast to communicate with centrally located DHCP servers. Since UDP broadcasts are typically blocked at router interfaces, the ip helper-address command is utilized to forward UDP request packets as UDP unicast packets to one or more pre-determined DHCP servers.

      For instance, if the desired DHCP server is located at ip address, the following command would be utilized to forward DHCP requests;

      R1#conf t
          Enter configuration commands, one per line. End with CNTL/Z.
          R1(config)#interface ethernet0/0
          R1(config-if)#ip helper-address

    • 5.1.b DHCP options (Basic overview and functionality)

    • 5.1.c Excluded addresses

    • 5.1.d Lease time

  • 5.2 Describe the types, features, and applications of ACLs

    An Access Control List (ACL) is a security measure for identifying and controlling specific network traffic. Access to particular resources can permitted or denied depending upon the individual permissions established within the control list. There are different types of ACLs, among the most commonly used are "named" or "numbered" and are applied with either standard or extended filtering. Access control lists must first be configured, then applied to the proper interfaces. Filtering may be applied to both inbound and outbound traffic.

    • 5.2.a Standard (editing and sequence numbers)

    • 5.2.b Extended

    • 5.2.c Named

    • 5.2.d Numbered

    • 5.2.e Log option

  • 5.3 Configure and verify ACLs in a network environment

    Configuring ACLs

    • 5.3.a Named

    • 5.3.b Numbered

    • 5.3.c Log option

  • 5.4 Identify the basic operation of NAT

    NAT (Network Address Translation) is the translation of one network's IP address information to that of another. NAT permits the use of internal subnet address for routing internal traffic, then translates these addresses to external addresses for transit across a routing device.

    • 5.4.a Purpose

    • 5.4.b Pool

    • 5.4.c Static

    • 5.4.d 1 to 1

    • 5.4.e Overloading

    • 5.4.f Source addressing

    • 5.4.g One-way NAT

  • 5.5 Configure and verify NAT for given network requirements

    Enable and Configure NAT

  • 5.6 Configure and verify NTP as a client

    The Network Time Protocol (NTP) is a networking protocol and software implementation for synchronizing the clocks of computer systems over packet-switched, variable-latency data networks.


ICND1 100-101 Study Guide