Cisco Packet Tracer 8.x tutorials
This Cisco Packet Tracer 8.2 tutorial describes two common use cases for radius authentication configuration on enterprise networks :
- Radius as a central authentication service for securing network devices admin access
- Radius as an authentication service for securing a WIFI network with WPA enterprise
Introduction
Frame Relay is a protocol standard for WAN internetworking which provides a fast and efficient method of transmitting packets through the network. Frame Relay offers an attractive alternative to both dedicated lines and X.25 networks for WAN links. The success of the Frame Relay protocol is based on the following two factors:
- Virtual circuits consume bandwidth only when they transport data. Consequently, many virtual circuits can exist across a given transmission line, which is an improvement compared to dedicated leased lines. In addition, each device can use more than the allowed bandwidth as necessary, and thus operate at higher speeds.
- The increased error-handling sophistication at end stations and the improved reliability of communication lines allows the Frame Relay protocol to discard bad frames and thus eliminate time-consuming error-handling processing.
Cisco Packet Tracer 8.2 includes a "Cloud-PT" device for WAN emulation. This device can be configured as a Frame Relay switch. Router are connected to the Frame Relay switch using serial connections. Virtual circuits, LMI types, and DLCI are configured using the Serial and Frame Relay tabs of the "Cloud-PT" device.
Introduction
DHCP service is a key component of your network infrastructure by allowing centralized ip address management on a single pool of servers. DHCP configuration is also part of CCNA and CCNP Enterprise certification curricula. This skill can be tested in lab environnement during exams ans it's important for students to get used to DHCP configuration before taking the exam.
Packet Tracer 8.2 implements two methods for setting up a DHCP server in your network :
- Configuration of DHCP pools on Cisco routers or multlayer switches.
- Configuration of a standalone DHCP server appliance on the network and usage of the "ip helper-address" command on network devices for DHCP traffic forwarding outside each local broadcast domain. This tutorial will describe this method for implementing DHCP service in your network.
DHCP server and DHCP client sould be in the same vlan to be able to communicate as the initial DHCP discover is a layer 2 broadcast packet to ff:ff:ff:ff:ff:ff MAC address. Cisco routers and layer 3 switches are able to act as DHCP relay and forward DHCP requests to a DHCP server located in another VLAN : a single DHCP server can now be deployed to deliver IP addresses to many subnet.
Introduction
Access Control Lists (ACL) are used to filter network traffic on Cisco routers. In order to filter network traffic, ACLs control if routed packets have to be forwarded or blocked at the ingress or egress router interface. The router checks each packet to determine whether to forward or drop the packet based on the criteria specified in the ACL applied to the interface.
What is Netflow?
Netflow is a network analysis protocol that was initially created by Cisco to give the ability to collect detailled informations about network traffic as it flows through a router interface.
The data processed by Netflow collectors provides the network administrator with detailled traffic informations such as the source and destination of the traffic, class of service, .... Netflow version 9 was standardized in 2008 as IPFIX by the IETF organization. This feature is used by network operators for billing network users.
NetFlow records are exported to a Netflow collector using User Datagram Protocol (UDP). The IP address and the destination UDP port of the NetFlow collector have to be configured on the sending device (router or l3 switch). The standard value is UDP port 2055, but other values like 9555 or 9995 can also be used.
