Skip to main content

Host name resolution / Configuring host tables / Configuration backup and documentation

Host name resolution

3.2.6  This page will explain how Cisco IOS performs host name resolution.
Host name resolution is the process that a computer system uses to associate a host name with an IP address.
In order to use host names to communicate with other IP devices, network devices such as routers must be able to associate the host names with IP addresses. A list of host names and their associated IP addresses is called a host table.
A host table might include all devices in a network organization. Each unique IP address can have a host name associated with it. The Cisco IOS software maintains a cache of host name-to-address mappings for use by EXEC commands. This cache speeds up the process of converting names to addresses.
Host names, unlike DNS names, are significant only on the router on which they are configured. The host table will allow the network administrator to type either the host name such as Auckland or the IP address to Telnet to a remote host.
The next page will explain how host tables are configured.

Configuration host tables 

3.2.7  This page will teach students how to configure a host table.
To assign host names to addresses, first enter global configuration mode. Issue the command ip host followed by the name of the destination and all IP addresses where the device can be reached. This maps the host name to each of its interface IP addresses. To test connectivity to the host, use a telnet or ping command with the name of the router or an IP address that is associated with the router name.
The procedure to configure a host table is as follows:
  1. Enter global configuration mode.
  2. Enter the ip host command followed by the name of the router and all IP addresses associated with the router interfaces.
  3. Repeat Step 2 until all routers in the network are entered.
  4. Save the configuration to NVRAM.
In the Lab Activities, students will configure host tables that identify routers and interfaces.
The next page explains how configuration files should be managed.
Configuration backup and Documentation

3.2.8 This page will discuss the backup and documentation of configuration files. 
The configuration of network devices determines how the network will behave. Management of device configuration includes the following tasks:
  • List and compare configuration files on running devices.
  • Store configuration files on network servers.
  • Perform software installations and upgrades.
Configuration files should be stored as backup files in the event of a problem. Configuration files can be stored on a network server, on a TFTP server, or on a disk stored in a safe place. Include documentation with the offline information.

Comments

Post a Comment

Popular posts from this blog

OSI layers / Peer-to-peer communications / TCP/IP model

OSI layers 2.3.4 This page discusses the seven layers of the OSI model. The OSI reference model is a framework that is used to understand how information travels throughout a network. The OSI reference model explains how packets travel through the various layers to another device on a network, even if the sender and destination have different types of network media. In the OSI reference model, there are seven numbered layers, each of which illustrates a particular network function. - Dividing the network into seven layers provides the following advantages: • It breaks network communication into smaller, more manageable parts. • It standardizes network components to allow multiple vendor development and support. • It allows different types of network hardware and software to communicate with each other. • It prevents changes in one layer from affecting other layers. • It divides network communication into smaller parts to make learning it easier to understand. In the foll...
Post a Comment
Read more

Advantages and disadvantages of link-state routing

Advantages and disadvantages of link-state routing 2.1.5  This page lists the advantages and disadvantages of link-state routing protocols. The following are advantages of link-state routing protocols:  Link-state protocols use cost metrics to choose paths through the network. The cost metric reflects the capacity of the links on those paths. Link-state protocols use triggered updates and LSA floods to immediately report changes in the network topology to all routers in the network. This leads to fast convergence times. Each router has a complete and synchronized picture of the network. Therefore, it is very difficult for routing loops to occur. Routers use the latest information to make the best routing decisions. The link-state database sizes can be minimized with careful network design. This leads to smaller Dijkstra calculations and faster convergence. Every router, at the very least, maps the topology of it...
Post a Comment
Read more

Ports for services

Ports for services 10.2.2  Services running on hosts must have a port number assigned to them so communication can occur. A remote host attempting to connect to a service expects that service to use specific transport layer protocols and ports. Some ports, which are defined in RFC 1700, are known as the well-known ports. These ports are reserved in both TCP and UDP.  These well-known ports define applications that run above the transport layer protocols. For example, a server that runs FTP will use ports 20 and 21 to forward TCP connections from clients to its FTP application. This allows the server to determine which service a client requests. TCP and UDP use port numbers to determine the correct service to which requests are forwarded. The next page will discuss ports in greater detail.
Post a Comment
Read more